diff --git a/validation-suite/backend/mercury/alembic/versions/202607110006_convert_user_role_enum_to_string.py b/validation-suite/backend/mercury/alembic/versions/202607110006_convert_user_role_enum_to_string.py
new file mode 100644
index 00000000..0a9ae074
--- /dev/null
+++ b/validation-suite/backend/mercury/alembic/versions/202607110006_convert_user_role_enum_to_string.py
@@ -0,0 +1,108 @@
+from __future__ import annotations
+
+from alembic import op
+import sqlalchemy as sa
+
+revision = "202607110006"
+down_revision = "202607110005"
+branch_labels = None
+depends_on = None
+
+ALLOWED_ROLES = ("admin", "pruefer", "mitarbeiter", "leser")
+
+
+def _other_columns_use_userrole(connection) -> bool:
+    result = connection.execute(
+        sa.text(
+            """
+            SELECT EXISTS (
+                SELECT 1
+                FROM pg_attribute a
+                JOIN pg_class c ON c.oid = a.attrelid
+                JOIN pg_type t ON t.oid = a.atttypid
+                JOIN pg_namespace n ON n.oid = c.relnamespace
+                WHERE t.typname = 'userrole'
+                  AND NOT (n.nspname = 'public' AND c.relname = 'users' AND a.attname = 'role')
+                  AND a.attnum > 0
+                  AND NOT a.attisdropped
+            )
+            """
+        )
+    )
+    return bool(result.scalar())
+
+
+def _normalize_roles(connection) -> None:
+    connection.execute(
+        sa.text(
+            """
+            UPDATE users
+            SET role = CASE upper(role::text)
+                WHEN 'ADMIN' THEN 'admin'
+                WHEN 'PRUEFER' THEN 'pruefer'
+                WHEN 'EMPLOYEE' THEN 'mitarbeiter'
+                WHEN 'MITARBEITER' THEN 'mitarbeiter'
+                WHEN 'AUDITOR' THEN 'leser'
+                WHEN 'LESER' THEN 'leser'
+                ELSE role::text
+            END
+            """
+        )
+    )
+    invalid_roles = connection.execute(
+        sa.text(
+            """
+            SELECT DISTINCT role::text
+            FROM users
+            WHERE role::text NOT IN ('admin', 'pruefer', 'mitarbeiter', 'leser')
+            """
+        ),
+    ).scalars().all()
+    if invalid_roles:
+        raise RuntimeError(f"Unknown user roles encountered during migration: {', '.join(sorted(invalid_roles))}")
+
+
+def upgrade() -> None:
+    connection = op.get_bind()
+    op.alter_column(
+        "users",
+        "role",
+        existing_type=sa.Enum(name="userrole"),
+        type_=sa.String(length=50),
+        existing_nullable=False,
+        existing_server_default=None,
+        postgresql_using="role::text",
+        nullable=False,
+    )
+    _normalize_roles(connection)
+    op.execute(sa.text("ALTER TABLE users ALTER COLUMN role SET DEFAULT 'mitarbeiter'"))
+    if not _other_columns_use_userrole(connection):
+        op.execute(sa.text("DROP TYPE IF EXISTS userrole"))
+
+
+def downgrade() -> None:
+    connection = op.get_bind()
+    op.execute(
+        sa.text(
+            "CREATE TYPE userrole AS ENUM ('admin', 'pruefer', 'mitarbeiter', 'leser')"
+        )
+    )
+    invalid_roles = connection.execute(
+        sa.text(
+            """
+            SELECT DISTINCT role
+            FROM users
+            WHERE role NOT IN ('admin', 'pruefer', 'mitarbeiter', 'leser')
+            """
+        ),
+    ).scalars().all()
+    if invalid_roles:
+        raise RuntimeError(f"Cannot downgrade user roles with invalid values: {', '.join(sorted(invalid_roles))}")
+    op.alter_column(
+        "users",
+        "role",
+        existing_type=sa.String(length=50),
+        type_=sa.Enum("admin", "pruefer", "mitarbeiter", "leser", name="userrole"),
+        nullable=False,
+    )
+    op.execute(sa.text("ALTER TABLE users ALTER COLUMN role SET DEFAULT 'mitarbeiter'::userrole"))
diff --git a/validation-suite/backend/mercury/alembic/versions/202607110007_add_user_deleted_at.py b/validation-suite/backend/mercury/alembic/versions/202607110007_add_user_deleted_at.py
new file mode 100644
index 00000000..8f02545a
--- /dev/null
+++ b/validation-suite/backend/mercury/alembic/versions/202607110007_add_user_deleted_at.py
@@ -0,0 +1,25 @@
+"""add deleted_at to users for soft delete
+
+Revision ID: 202607110007
+Revises: 202607110006
+Create Date: 2026-07-11 00:07:00.000000
+"""
+
+from __future__ import annotations
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = "202607110007"
+down_revision = "202607110006"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column("users", sa.Column("deleted_at", sa.DateTime(timezone=True), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("users", "deleted_at")
diff --git a/validation-suite/backend/mercury/app/api/v1/__pycache__/domain.cpython-313.pyc b/validation-suite/backend/mercury/app/api/v1/__pycache__/domain.cpython-313.pyc
index 4df9b1ec..ec283d1d 100644
Binary files a/validation-suite/backend/mercury/app/api/v1/__pycache__/domain.cpython-313.pyc and b/validation-suite/backend/mercury/app/api/v1/__pycache__/domain.cpython-313.pyc differ
diff --git a/validation-suite/backend/mercury/app/api/v1/domain.py b/validation-suite/backend/mercury/app/api/v1/domain.py
index 11ad978a..abdb6d4c 100644
--- a/validation-suite/backend/mercury/app/api/v1/domain.py
+++ b/validation-suite/backend/mercury/app/api/v1/domain.py
@@ -6,13 +6,14 @@ import json
 import logging
 import shutil
 import uuid
+from datetime import UTC, datetime
 from pathlib import Path
 
-from fastapi import APIRouter, Depends, File, Form, Query, Response, UploadFile
+from fastapi import APIRouter, Depends, File, Form, HTTPException, Query, Response, UploadFile
 from fastapi.encoders import jsonable_encoder
 from fastapi.responses import FileResponse, HTMLResponse, JSONResponse
 from sqlalchemy import func, select
-from sqlalchemy.exc import IntegrityError
+from sqlalchemy.exc import IntegrityError, ProgrammingError
 from sqlalchemy.orm import Session
 
 from app.api.dependencies import current_admin, current_user
@@ -560,7 +561,7 @@ def _user_payload(user: User) -> dict:
         "email": user.email,
         "first_name": user.first_name,
         "last_name": user.last_name,
-        "role": user.role,
+        "role": UserRole(user.role),
         "is_active": user.is_active,
         "must_change_password": user.must_change_password,
         "last_login_at": user.last_login_at,
@@ -581,6 +582,7 @@ def list_users(
     _: User = Depends(current_admin),
 ):
     query = select(User)
+    query = query.where(User.deleted_at.is_(None))
     if search:
         term = f"%{search.strip()}%"
         query = query.where(
@@ -605,8 +607,9 @@ def list_users(
     sort_column = sort_columns.get(sort_by, User.created_at)
     query = query.order_by(sort_column.asc() if sort_order.lower() == "asc" else sort_column.desc())
     total = session.scalar(select(func.count()).select_from(query.order_by(None).subquery())) or 0
+    pages = max((total + page_size - 1) // page_size, 1)
     items = list(session.scalars(query.offset((page - 1) * page_size).limit(page_size)))
-    return {"items": items, "total": total, "page": page, "page_size": page_size}
+    return {"items": items, "total": total, "page": page, "page_size": page_size, "pages": pages}
 
 
 @router.post("/users", status_code=201)
@@ -615,26 +618,47 @@ def create_user(payload: UserCreate, session: Session = Depends(get_session), _:
     import secrets
     from app.models.user import User
 
+    normalized_email = payload.email.strip().lower()
+    logger.debug("create_user request email=%s normalized_email=%s", payload.email, normalized_email)
+    existing = session.scalar(select(User).where(func.lower(User.email) == normalized_email))
+    logger.debug("create_user select result=%s count=%s", bool(existing), 1 if existing else 0)
+    if existing is not None:
+        raise HTTPException(status_code=409, detail="Die E-Mail-Adresse wird bereits verwendet.")
+
     temporary_password = payload.temporary_password or secrets.token_urlsafe(12)
-    user = User(
-        email=payload.email.lower(),
-        first_name=payload.first_name,
-        last_name=payload.last_name,
-        role=payload.role.value,
-        password_hash=hash_password(temporary_password),
-        is_active=payload.is_active,
-        must_change_password=payload.must_change_password,
-    )
-    session.add(user)
-    session.commit()
-    session.refresh(user)
-    return JSONResponse(content={"temporary_password": temporary_password, "user": jsonable_encoder(user)}, status_code=201)
+    try:
+        user = User(
+            email=normalized_email,
+            first_name=payload.first_name,
+            last_name=payload.last_name,
+            role=payload.role.value,
+            password_hash=hash_password(temporary_password),
+            is_active=payload.is_active,
+            must_change_password=payload.must_change_password,
+        )
+        logger.debug("create_user insert email=%s", normalized_email)
+        session.add(user)
+        session.commit()
+        logger.debug("create_user commit ok email=%s id=%s", normalized_email, user.id)
+        session.refresh(user)
+        logger.debug("create_user response email=%s status=201", normalized_email)
+        return JSONResponse(
+            content={"temporary_password": temporary_password, "user": jsonable_encoder(user)},
+            status_code=201,
+        )
+    except IntegrityError as exc:
+        session.rollback()
+        logger.exception("create_user integrity error email=%s", normalized_email)
+        raise HTTPException(status_code=409, detail="Die E-Mail-Adresse wird bereits verwendet.") from exc
+    except ProgrammingError as exc:
+        session.rollback()
+        raise HTTPException(status_code=422, detail="Die Benutzerrolle ist ungültig.") from exc
 
 
 @router.get("/users/{item_id}", response_model=UserRead)
 def get_user(item_id: str, session: Session = Depends(get_session), _: User = Depends(current_admin)):
     user = session.get(User, item_id)
-    if user is None:
+    if user is None or user.deleted_at is not None:
         raise HTTPException(status_code=404, detail="Resource not found")
     return user
 
@@ -642,7 +666,7 @@ def get_user(item_id: str, session: Session = Depends(get_session), _: User = De
 @router.put("/users/{item_id}", response_model=UserRead)
 def update_user(item_id: str, payload: UserUpdate, session: Session = Depends(get_session), me: User = Depends(current_admin)):
     user = session.get(User, item_id)
-    if user is None:
+    if user is None or user.deleted_at is not None:
         raise HTTPException(status_code=404, detail="Resource not found")
     if user.id == me.id and not payload.is_active:
         raise HTTPException(status_code=409, detail="Own admin account cannot be deactivated")
@@ -651,44 +675,58 @@ def update_user(item_id: str, payload: UserUpdate, session: Session = Depends(ge
     ) or 0
     if user.role == UserRole.ADMIN.value and active_admins <= 1 and (not payload.is_active or payload.role != UserRole.ADMIN.value):
         raise HTTPException(status_code=409, detail="Der letzte aktive ADMIN darf nicht deaktiviert oder herabgestuft werden.")
-    user.first_name = payload.first_name
-    user.last_name = payload.last_name
-    user.email = payload.email.lower()
-    user.role = payload.role.value
-    user.is_active = payload.is_active
-    user.must_change_password = payload.must_change_password
-    session.commit()
-    session.refresh(user)
-    return user
+    try:
+        normalized_email = payload.email.strip().lower()
+        logger.debug("update_user request id=%s email=%s normalized_email=%s", item_id, payload.email, normalized_email)
+        existing = session.scalar(
+            select(User).where(func.lower(User.email) == normalized_email, User.id != user.id)
+        )
+        logger.debug("update_user select result=%s count=%s", bool(existing), 1 if existing else 0)
+        if existing is not None:
+            raise HTTPException(status_code=409, detail="Die E-Mail-Adresse wird bereits verwendet.")
+        user.first_name = payload.first_name
+        user.last_name = payload.last_name
+        user.email = normalized_email
+        user.role = payload.role.value
+        user.is_active = payload.is_active
+        user.must_change_password = payload.must_change_password
+        logger.debug("update_user commit start id=%s email=%s", user.id, normalized_email)
+        session.commit()
+        logger.debug("update_user commit ok id=%s email=%s", user.id, normalized_email)
+        session.refresh(user)
+        return user
+    except IntegrityError as exc:
+        session.rollback()
+        logger.exception("update_user integrity error id=%s email=%s", item_id, payload.email)
+        raise HTTPException(status_code=409, detail="Die E-Mail-Adresse wird bereits verwendet.") from exc
+    except ProgrammingError as exc:
+        session.rollback()
+        raise HTTPException(status_code=422, detail="Die Benutzerrolle ist ungültig.") from exc
 
 
-@router.post("/users/{item_id}/deactivate", response_model=UserRead)
-def deactivate_user(item_id: str, session: Session = Depends(get_session), me: User = Depends(current_admin)):
+@router.delete("/users/{item_id}", status_code=204)
+def delete_user(item_id: str, session: Session = Depends(get_session), me: User = Depends(current_admin)):
     user = session.get(User, item_id)
-    if user is None:
+    if user is None or user.deleted_at is not None:
         raise HTTPException(status_code=404, detail="Resource not found")
     if user.id == me.id:
-        raise HTTPException(status_code=409, detail="Own admin account cannot be deactivated")
+        raise HTTPException(status_code=409, detail="Das eigene Benutzerkonto kann nicht geloescht werden.")
     active_admins = session.scalar(
         select(func.count()).select_from(User).where(User.role == UserRole.ADMIN.value, User.is_active.is_(True))
     ) or 0
     if user.role == UserRole.ADMIN.value and active_admins <= 1:
-        raise HTTPException(status_code=409, detail="Der letzte aktive ADMIN darf nicht deaktiviert werden.")
+        raise HTTPException(status_code=409, detail="Der letzte aktive ADMIN darf nicht geloescht werden.")
+    referenced_validations = session.scalar(
+        select(func.count()).select_from(Validation).where(Validation.examiner_id == user.id)
+    ) or 0
+    if referenced_validations == 0:
+        session.delete(user)
+        session.commit()
+        return Response(status_code=204)
     user.is_active = False
+    user.deleted_at = datetime.now(UTC)
     session.commit()
-    session.refresh(user)
-    return user
-
-
-@router.post("/users/{item_id}/activate", response_model=UserRead)
-def activate_user(item_id: str, session: Session = Depends(get_session), _: User = Depends(current_admin)):
-    user = session.get(User, item_id)
-    if user is None:
-        raise HTTPException(status_code=404, detail="Resource not found")
-    user.is_active = True
-    session.commit()
-    session.refresh(user)
-    return user
+    return Response(status_code=204)
 
 
 @router.post("/users/{item_id}/reset-password")
@@ -697,7 +735,7 @@ def reset_user_password(item_id: str, session: Session = Depends(get_session), _
     from app.core.security import hash_password
 
     user = session.get(User, item_id)
-    if user is None:
+    if user is None or user.deleted_at is not None:
         raise HTTPException(status_code=404, detail="Resource not found")
     temporary_password = secrets.token_urlsafe(12)
     user.password_hash = hash_password(temporary_password)
diff --git a/validation-suite/backend/mercury/app/models/__pycache__/user.cpython-313.pyc b/validation-suite/backend/mercury/app/models/__pycache__/user.cpython-313.pyc
index ffea153c..c13cecac 100644
Binary files a/validation-suite/backend/mercury/app/models/__pycache__/user.cpython-313.pyc and b/validation-suite/backend/mercury/app/models/__pycache__/user.cpython-313.pyc differ
diff --git a/validation-suite/backend/mercury/app/models/user.py b/validation-suite/backend/mercury/app/models/user.py
index e68750cc..a2eea975 100644
--- a/validation-suite/backend/mercury/app/models/user.py
+++ b/validation-suite/backend/mercury/app/models/user.py
@@ -4,7 +4,7 @@ import enum
 from datetime import datetime
 
 from sqlalchemy import Boolean, DateTime, String
-from sqlalchemy.orm import Mapped, mapped_column
+from sqlalchemy.orm import Mapped, mapped_column, validates
 
 from app.db.base import Base, TimestampMixin, UUIDMixin
 
@@ -20,15 +20,21 @@ class User(Base, UUIDMixin, TimestampMixin):
     __tablename__ = "users"
 
     email: Mapped[str] = mapped_column(String(255), unique=True, index=True)
+    full_name: Mapped[str] = mapped_column(String(160), nullable=False)
     first_name: Mapped[str] = mapped_column(String(80))
     last_name: Mapped[str] = mapped_column(String(80))
-    role: Mapped[str] = mapped_column(String(40), default=UserRole.MITARBEITER.value)
+    role: Mapped[str] = mapped_column(String(50), nullable=False, default=UserRole.MITARBEITER.value)
     password_hash: Mapped[str] = mapped_column(String(255))
     is_active: Mapped[bool] = mapped_column(Boolean, default=True)
     must_change_password: Mapped[bool] = mapped_column(Boolean, default=True)
+    deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
     last_login_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
     password_changed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
 
-    @property
-    def full_name(self) -> str:
-        return f"{self.first_name} {self.last_name}".strip()
+    @validates("first_name", "last_name")
+    def _sync_full_name(self, key: str, value: str) -> str:
+        first_name = value if key == "first_name" else getattr(self, "first_name", None)
+        last_name = value if key == "last_name" else getattr(self, "last_name", None)
+        if first_name is not None and last_name is not None:
+            self.full_name = f"{first_name} {last_name}".strip()
+        return value
diff --git a/validation-suite/backend/mercury/app/repositories/__pycache__/domain.cpython-313.pyc b/validation-suite/backend/mercury/app/repositories/__pycache__/domain.cpython-313.pyc
index 20c3149e..9a5359d5 100644
Binary files a/validation-suite/backend/mercury/app/repositories/__pycache__/domain.cpython-313.pyc and b/validation-suite/backend/mercury/app/repositories/__pycache__/domain.cpython-313.pyc differ
diff --git a/validation-suite/backend/mercury/app/repositories/domain.py b/validation-suite/backend/mercury/app/repositories/domain.py
index efec5848..1dc630ae 100644
--- a/validation-suite/backend/mercury/app/repositories/domain.py
+++ b/validation-suite/backend/mercury/app/repositories/domain.py
@@ -18,7 +18,7 @@ class UserRepository(Repository[User]):
     model = User
 
     def by_email(self, email: str) -> User | None:
-        return self.session.scalar(select(User).where(User.email == email.lower()))
+        return self.session.scalar(select(User).where(User.email == email.strip().lower()))
 
 
 class CustomerRepository(Repository[Customer]):
diff --git a/validation-suite/backend/mercury/app/schemas/__pycache__/common.cpython-313.pyc b/validation-suite/backend/mercury/app/schemas/__pycache__/common.cpython-313.pyc
index 93a93485..49a71948 100644
Binary files a/validation-suite/backend/mercury/app/schemas/__pycache__/common.cpython-313.pyc and b/validation-suite/backend/mercury/app/schemas/__pycache__/common.cpython-313.pyc differ
diff --git a/validation-suite/backend/mercury/app/schemas/common.py b/validation-suite/backend/mercury/app/schemas/common.py
index 9c7db7c1..eb939ee0 100644
--- a/validation-suite/backend/mercury/app/schemas/common.py
+++ b/validation-suite/backend/mercury/app/schemas/common.py
@@ -23,3 +23,4 @@ class PaginatedResponse(BaseModel, Generic[T]):
     total: int
     page: int
     page_size: int
+    pages: int
diff --git a/validation-suite/backend/mercury/app/services/__pycache__/auth_service.cpython-313.pyc b/validation-suite/backend/mercury/app/services/__pycache__/auth_service.cpython-313.pyc
index c054dcf8..406527a9 100644
Binary files a/validation-suite/backend/mercury/app/services/__pycache__/auth_service.cpython-313.pyc and b/validation-suite/backend/mercury/app/services/__pycache__/auth_service.cpython-313.pyc differ
diff --git a/validation-suite/backend/mercury/app/services/auth_service.py b/validation-suite/backend/mercury/app/services/auth_service.py
index 0b37bfb0..c17b06db 100644
--- a/validation-suite/backend/mercury/app/services/auth_service.py
+++ b/validation-suite/backend/mercury/app/services/auth_service.py
@@ -23,7 +23,7 @@ class AuthService:
                 detail="Invalid credentials",
                 headers={"WWW-Authenticate": "Bearer"},
             )
-        if not user.is_active:
+        if not user.is_active or user.deleted_at is not None:
             raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Inactive user")
         user.last_login_at = datetime.now(UTC)
         self.users.session.commit()
diff --git a/validation-suite/backend/mercury/tests/__pycache__/test_validation_workflow.cpython-313-pytest-8.3.4.pyc b/validation-suite/backend/mercury/tests/__pycache__/test_validation_workflow.cpython-313-pytest-8.3.4.pyc
index ba270046..73c3851a 100644
Binary files a/validation-suite/backend/mercury/tests/__pycache__/test_validation_workflow.cpython-313-pytest-8.3.4.pyc and b/validation-suite/backend/mercury/tests/__pycache__/test_validation_workflow.cpython-313-pytest-8.3.4.pyc differ
diff --git a/validation-suite/backend/mercury/tests/test_validation_workflow.py b/validation-suite/backend/mercury/tests/test_validation_workflow.py
index 647dd59f..be2648c5 100644
--- a/validation-suite/backend/mercury/tests/test_validation_workflow.py
+++ b/validation-suite/backend/mercury/tests/test_validation_workflow.py
@@ -1,9 +1,11 @@
 from __future__ import annotations
 
+import json
 import re
 from datetime import date
 from pathlib import Path
 
+import pytest
 from sqlalchemy import create_engine, select
 from sqlalchemy.orm import Session
 
@@ -19,8 +21,9 @@ from app.services.validation_workflow import ValidationWorkflowService
 from app.services.auth_service import AuthService
 from app.services.reference_masterdata import ReferenceMasterdataImportService
 from app.api.v1.auth import login as auth_login
+from app.api.v1 import domain as domain_api
 from app.schemas.auth import LoginRequest
-from app.schemas.domain import ValidationCreate
+from app.schemas.domain import UserCreate, UserUpdate, ValidationCreate
 from app.modules.orion.service import OrionReportService
 from app.modules.orion.assets import SCHUBAMED_LOGO_PATH, schubamed_logo_uri
 from app.modules.orion.template_service import REPORT_SECTIONS, ReportTemplateService
@@ -212,6 +215,319 @@ def test_user_model_supports_password_management_fields():
     assert user.role == UserRole.PRUEFER
 
 
+def test_admin_appears_in_user_list():
+    db = session()
+    admin = User(
+        email="admin@schubamed.de",
+        first_name="Admin",
+        last_name="User",
+        role=UserRole.ADMIN.value,
+        password_hash="hash",
+        is_active=True,
+        must_change_password=False,
+    )
+    db.add(admin)
+    db.flush()
+
+    result = domain_api.list_users(session=db, _=admin, page=1, page_size=20, search=None, role=None, active=None, sort_by="created_at", sort_order="desc")
+
+    assert result["total"] == 1
+    assert result["pages"] == 1
+    assert any(item.id == admin.id for item in result["items"])
+
+
+def test_user_list_pagination_and_filters_work():
+    db = session()
+    admin = User(
+        email="admin@schubamed.de",
+        first_name="Admin",
+        last_name="User",
+        role=UserRole.ADMIN.value,
+        password_hash="hash",
+        is_active=True,
+        must_change_password=False,
+    )
+    inactive = User(
+        email="inactive@schubamed.de",
+        first_name="Inactive",
+        last_name="User",
+        role=UserRole.LESER.value,
+        password_hash="hash",
+        is_active=False,
+        must_change_password=False,
+    )
+    db.add_all([admin, inactive])
+    db.flush()
+
+    result = domain_api.list_users(session=db, _=admin, page=1, page_size=1, search=None, role=None, active=None, sort_by="created_at", sort_order="desc")
+    assert result["total"] == 2
+    assert result["pages"] == 2
+    assert len(result["items"]) == 1
+
+    active_only = domain_api.list_users(session=db, _=admin, page=1, page_size=20, search=None, role=None, active=True, sort_by="created_at", sort_order="desc")
+    assert active_only["total"] == 1
+    assert all(item.is_active for item in active_only["items"])
+
+    inactive_only = domain_api.list_users(session=db, _=admin, page=1, page_size=20, search=None, role=None, active=False, sort_by="created_at", sort_order="desc")
+    assert inactive_only["total"] == 1
+    assert all(not item.is_active for item in inactive_only["items"])
+
+    role_filtered = domain_api.list_users(session=db, _=admin, page=1, page_size=20, search=None, role=UserRole.ADMIN.value, active=None, sort_by="created_at", sort_order="desc")
+    assert role_filtered["total"] == 1
+    assert role_filtered["items"][0].role == UserRole.ADMIN.value
+
+
+def test_admin_can_create_users_with_supported_roles():
+    db = session()
+    admin = User(
+        email="admin@schubamed.de",
+        first_name="Admin",
+        last_name="User",
+        role=UserRole.ADMIN.value,
+        password_hash="hash",
+        is_active=True,
+        must_change_password=False,
+    )
+    db.add(admin)
+    db.flush()
+
+    for role in (UserRole.MITARBEITER, UserRole.PRUEFER, UserRole.LESER):
+        response = domain_api.create_user(
+            UserCreate(
+                email=f"{role.value}@schubamed.de",
+                first_name="Test",
+                last_name="User",
+                role=role,
+                is_active=True,
+                must_change_password=False,
+                temporary_password="TempPassword123!",
+            ),
+            session=db,
+            _=admin,
+        )
+        payload = json.loads(response.body)
+        assert response.status_code == 201
+        assert payload["user"]["role"] == role.value
+        assert db.scalar(select(User).where(User.email == f"{role.value}@schubamed.de")) is not None
+
+
+def test_create_user_trims_and_normalizes_email():
+    db = session()
+    admin = User(
+        email="admin@schubamed.de",
+        first_name="Admin",
+        last_name="User",
+        role=UserRole.ADMIN.value,
+        password_hash="hash",
+        is_active=True,
+        must_change_password=False,
+    )
+    db.add(admin)
+    db.flush()
+
+    response = domain_api.create_user(
+        UserCreate(
+            email="  New.User@Schubamed.DE  ",
+            first_name="New",
+            last_name="User",
+            role=UserRole.MITARBEITER,
+            is_active=True,
+            must_change_password=False,
+            temporary_password="TempPassword123!",
+        ),
+        session=db,
+        _=admin,
+    )
+
+    payload = json.loads(response.body)
+    assert response.status_code == 201
+    assert payload["user"]["email"] == "new.user@schubamed.de"
+    assert db.scalar(select(User).where(User.email == "new.user@schubamed.de")) is not None
+
+
+def test_duplicate_email_returns_409_and_rolls_back_session():
+    from fastapi import HTTPException
+
+    db = session()
+    admin = User(
+        email="admin@schubamed.de",
+        first_name="Admin",
+        last_name="User",
+        role=UserRole.ADMIN.value,
+        password_hash="hash",
+        is_active=True,
+        must_change_password=False,
+    )
+    db.add(admin)
+    db.flush()
+
+    first = domain_api.create_user(
+        UserCreate(
+            email="duplicate@schubamed.de",
+            first_name="First",
+            last_name="User",
+            role=UserRole.MITARBEITER,
+            is_active=True,
+            must_change_password=False,
+            temporary_password="TempPassword123!",
+        ),
+        session=db,
+        _=admin,
+    )
+    assert first.status_code == 201
+
+    with pytest.raises(HTTPException) as exc_info:
+        domain_api.create_user(
+            UserCreate(
+                email="duplicate@schubamed.de",
+                first_name="Second",
+                last_name="User",
+                role=UserRole.PRUEFER,
+                is_active=True,
+                must_change_password=False,
+                temporary_password="TempPassword123!",
+            ),
+            session=db,
+            _=admin,
+        )
+    assert exc_info.value.status_code == 409
+
+    follow_up = domain_api.create_user(
+        UserCreate(
+            email="fresh@schubamed.de",
+            first_name="Fresh",
+            last_name="User",
+            role=UserRole.LESER,
+            is_active=True,
+            must_change_password=False,
+            temporary_password="TempPassword123!",
+        ),
+        session=db,
+        _=admin,
+    )
+    assert follow_up.status_code == 201
+
+
+def test_update_user_keeps_same_email_without_false_duplicate():
+    db = session()
+    admin = User(
+        email="admin@schubamed.de",
+        first_name="Admin",
+        last_name="User",
+        role=UserRole.ADMIN.value,
+        password_hash="hash",
+        is_active=True,
+        must_change_password=False,
+    )
+    target = User(
+        email="target@schubamed.de",
+        first_name="Target",
+        last_name="User",
+        role=UserRole.MITARBEITER.value,
+        password_hash="hash",
+        is_active=True,
+        must_change_password=False,
+    )
+    db.add_all([admin, target])
+    db.flush()
+
+    response = domain_api.update_user(
+        target.id,
+        UserUpdate(
+            first_name="Target",
+            last_name="User",
+            email="target@schubamed.de",
+            role=UserRole.MITARBEITER,
+            is_active=True,
+            must_change_password=False,
+        ),
+        session=db,
+        me=admin,
+    )
+
+    assert response.email == "target@schubamed.de"
+    assert response.id == target.id
+
+
+def test_delete_user_without_references_removes_row():
+    db = session()
+    admin = User(
+        email="admin@schubamed.de",
+        first_name="Admin",
+        last_name="User",
+        role=UserRole.ADMIN.value,
+        password_hash="hash",
+        is_active=True,
+        must_change_password=False,
+    )
+    user = User(
+        email="delete-me@schubamed.de",
+        first_name="Delete",
+        last_name="Me",
+        role=UserRole.MITARBEITER.value,
+        password_hash="hash",
+        is_active=True,
+        must_change_password=False,
+    )
+    db.add_all([admin, user])
+    db.flush()
+
+    response = domain_api.delete_user(user.id, session=db, me=admin)
+
+    assert response.status_code == 204
+    assert db.get(User, user.id) is None
+
+
+def test_delete_user_with_validation_reference_soft_deletes_row():
+    db = session()
+    customer, location, device = seed(db)
+    admin = User(
+        email="admin@schubamed.de",
+        first_name="Admin",
+        last_name="User",
+        role=UserRole.ADMIN.value,
+        password_hash="hash",
+        is_active=True,
+        must_change_password=False,
+    )
+    examiner = User(
+        email="examiner@schubamed.de",
+        first_name="Examiner",
+        last_name="User",
+        role=UserRole.PRUEFER.value,
+        password_hash="hash",
+        is_active=True,
+        must_change_password=False,
+    )
+    validation = valid_validation(customer, location, device)
+    db.add_all([admin, examiner, validation])
+    db.flush()
+    validation.examiner_id = examiner.id
+    db.flush()
+
+    response = domain_api.delete_user(examiner.id, session=db, me=admin)
+
+    assert response.status_code == 204
+    db.refresh(examiner)
+    assert examiner.deleted_at is not None
+    assert examiner.is_active is False
+    listed = domain_api.list_users(session=db, _=admin, page=1, page_size=20, search=None, role=None, active=None, sort_by="created_at", sort_order="desc")
+    assert all(item.id != examiner.id for item in listed["items"])
+
+
+def test_invalid_user_role_is_rejected_by_schema():
+    with pytest.raises(Exception):
+        UserCreate(
+            email="bad-role@schubamed.de",
+            first_name="Bad",
+            last_name="Role",
+            role="invalid-role",  # type: ignore[arg-type]
+            is_active=True,
+            must_change_password=False,
+            temporary_password="TempPassword123!",
+        )
+
+
 def test_login_updates_last_login_at():
     from app.core.security import hash_password
 
diff --git a/validation-suite/frontend/atlas/app/(app)/dashboard/page.tsx b/validation-suite/frontend/atlas/app/(app)/dashboard/page.tsx
index e1961695..fa8ee003 100644
--- a/validation-suite/frontend/atlas/app/(app)/dashboard/page.tsx
+++ b/validation-suite/frontend/atlas/app/(app)/dashboard/page.tsx
@@ -24,7 +24,7 @@ type DashboardData = {
 };
 
 const primaryCards = [
-  { label: "Neue Validierung", value: "Starten", href: "/validations/new", icon: Plus },
+  { label: "Neue Validierung starten", value: "Schnellstart", href: "/validations/quick-start", icon: Plus },
   { label: "Validierungen", key: "validations", href: "/validations", icon: ClipboardList },
   { label: "Kunden", key: "customers", href: "/customers", icon: Users },
   { label: "Geraete", key: "devices", href: "/devices", icon: Stethoscope },
diff --git a/validation-suite/frontend/atlas/app/(app)/users/page.tsx b/validation-suite/frontend/atlas/app/(app)/users/page.tsx
index 00f36109..022a7990 100644
--- a/validation-suite/frontend/atlas/app/(app)/users/page.tsx
+++ b/validation-suite/frontend/atlas/app/(app)/users/page.tsx
@@ -2,12 +2,13 @@
 
 import { zodResolver } from "@hookform/resolvers/zod";
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
-import { Check, KeyRound, RotateCcw, Search, UserPlus2 } from "lucide-react";
-import { useMemo, useState } from "react";
+import { Copy, RotateCcw, Search, Trash2, UserPlus2, X } from "lucide-react";
+import { useState } from "react";
 import { useForm } from "react-hook-form";
 import { z } from "zod";
 import { useAuth } from "@/components/auth";
 import { apiDelete, apiFetch, apiGet, Paginated, User } from "@/lib/api";
+import { buildUsersQueryParams } from "@/lib/users-query";
 
 const schema = z.object({
   first_name: z.string().min(1, "Vorname erforderlich"),
@@ -33,12 +34,14 @@ export default function UsersPage() {
   const client = useQueryClient();
   const [search, setSearch] = useState("");
   const [role, setRole] = useState("");
-  const [active, setActive] = useState("");
+  const [active, setActive] = useState<"all" | "active" | "inactive">("all");
   const [page, setPage] = useState(1);
   const [sortBy, setSortBy] = useState("created_at");
   const [sortOrder, setSortOrder] = useState<"asc" | "desc">("desc");
   const [editing, setEditing] = useState<User | null>(null);
   const [temporaryPassword, setTemporaryPassword] = useState("");
+  const [temporaryPasswordOpen, setTemporaryPasswordOpen] = useState(false);
+  const [deleteTarget, setDeleteTarget] = useState<User | null>(null);
   const [message, setMessage] = useState("");
   const [error, setError] = useState("");
 
@@ -55,26 +58,30 @@ export default function UsersPage() {
     }
   });
 
-  const queryKey = useMemo(
-    () => ["users", token, page, search, role, active, sortBy, sortOrder],
-    [token, page, search, role, active, sortBy, sortOrder]
-  );
-
   const users = useQuery({
-    queryKey,
+    queryKey: ["users", page, 20, search, role, active, sortBy, sortOrder],
     queryFn: () =>
       apiGet<Paginated<User>>(
-        `/users?page=${page}&page_size=10&search=${encodeURIComponent(search)}&role=${encodeURIComponent(role)}&active=${encodeURIComponent(active)}&sort_by=${encodeURIComponent(sortBy)}&sort_order=${sortOrder}`,
+        `/users?${buildUsersQueryParams({
+          page,
+          pageSize: 20,
+          search,
+          role,
+          active: active === "all" ? undefined : active === "active",
+          sortBy,
+          sortOrder
+        }).toString()}`,
         token ?? ""
       ),
     enabled: Boolean(token)
   });
+  const pages = users.data?.pages ?? Math.max(1, Math.ceil((users.data?.total ?? 0) / (users.data?.page_size ?? 20)));
 
   const saveMutation = useMutation({
     mutationFn: async (values: UserForm) => {
       const payload = {
         ...values,
-        email: values.email.toLowerCase()
+        email: values.email.trim().toLowerCase()
       };
       if (editing) {
         return apiFetch<User>(`/users/${editing.id}`, token ?? "", { method: "PUT", body: JSON.stringify(payload) });
@@ -85,31 +92,38 @@ export default function UsersPage() {
       });
     },
     onSuccess: async (created) => {
+      const isCreate = !editing;
       if (!editing) {
         setTemporaryPassword((created as { temporary_password?: string }).temporary_password ?? "");
+      } else {
+        setTemporaryPassword("");
       }
       setMessage(editing ? "Benutzer gespeichert" : "Benutzer angelegt");
       setError("");
       setEditing(null);
+      setTemporaryPasswordOpen(isCreate && Boolean((created as { temporary_password?: string }).temporary_password));
       form.reset();
       await client.invalidateQueries({ queryKey: ["users"] });
     },
     onError: (err: Error) => setError(err.message)
   });
 
-  const deactivateMutation = useMutation({
-    mutationFn: (item: User) => apiFetch<User>(`/users/${item.id}/deactivate`, token ?? "", { method: "POST" }),
-    onSuccess: () => client.invalidateQueries({ queryKey: ["users"] })
-  });
-  const activateMutation = useMutation({
-    mutationFn: (item: User) => apiFetch<User>(`/users/${item.id}/activate`, token ?? "", { method: "POST" }),
-    onSuccess: () => client.invalidateQueries({ queryKey: ["users"] })
+  const deleteMutation = useMutation({
+    mutationFn: (item: User) => apiDelete(`/users/${item.id}`, token ?? ""),
+    onSuccess: async () => {
+      setMessage("Benutzer geloescht");
+      setError("");
+      setDeleteTarget(null);
+      await client.invalidateQueries({ queryKey: ["users"] });
+    },
+    onError: (err: Error) => setError(err.message)
   });
   const resetMutation = useMutation({
     mutationFn: (item: User) => apiFetch<{ temporary_password: string }>(`/users/${item.id}/reset-password`, token ?? "", { method: "POST" }),
     onSuccess: (result) => {
       setTemporaryPassword(result.temporary_password);
       setMessage("Temporäres Passwort erzeugt");
+      setTemporaryPasswordOpen(true);
     }
   });
 
@@ -135,6 +149,11 @@ export default function UsersPage() {
     });
   }
 
+  function submit(values: UserForm) {
+    if (saveMutation.isPending) return;
+    saveMutation.mutate(values);
+  }
+
   return (
     <div className="space-y-6">
       <header className="flex flex-col gap-3 md:flex-row md:items-center md:justify-between">
@@ -154,10 +173,10 @@ export default function UsersPage() {
             <option value="">Alle Rollen</option>
             {Object.entries(roleLabels).map(([value, label]) => <option key={value} value={value}>{label}</option>)}
           </select>
-          <select value={active} onChange={(e) => setActive(e.target.value)} className="h-12 rounded-lg border border-border px-3">
-            <option value="">Alle Status</option>
-            <option value="true">Aktiv</option>
-            <option value="false">Inaktiv</option>
+          <select value={active} onChange={(e) => setActive(e.target.value as "all" | "active" | "inactive")} className="h-12 rounded-lg border border-border px-3">
+            <option value="all">Alle Status</option>
+            <option value="active">Aktiv</option>
+            <option value="inactive">Inaktiv</option>
           </select>
           <select value={sortBy} onChange={(e) => setSortBy(e.target.value)} className="h-12 rounded-lg border border-border px-3">
             <option value="created_at">Erstellt am</option>
@@ -173,6 +192,14 @@ export default function UsersPage() {
         </div>
       </section>
       <section className="overflow-hidden rounded-lg border border-border bg-surface shadow-soft">
+        {users.isLoading ? (
+          <div className="flex items-center gap-3 px-5 py-6 text-sm text-text-light">
+            <span className="spinner" />
+            Benutzer werden geladen...
+          </div>
+        ) : users.isError ? (
+          <div className="px-5 py-6 text-sm text-danger">Benutzer konnten nicht geladen werden.</div>
+        ) : null}
         <div className="overflow-x-auto">
           <table className="min-w-full text-left text-sm">
             <thead className="bg-background text-xs uppercase text-text-light">
@@ -187,27 +214,31 @@ export default function UsersPage() {
               </tr>
             </thead>
             <tbody className="divide-y divide-border">
-              {(users.data?.items ?? []).map((item) => (
-                <tr key={item.id}>
-                  <td className="px-5 py-4">{item.first_name} {item.last_name}</td>
-                  <td className="px-5 py-4">{item.email}</td>
-                  <td className="px-5 py-4">{roleLabels[item.role]}</td>
-                  <td className="px-5 py-4">{item.is_active ? "Aktiv" : "Inaktiv"}</td>
-                  <td className="px-5 py-4">{item.last_login_at ?? "nicht erfasst"}</td>
-                  <td className="px-5 py-4">{item.password_changed_at ?? "nicht erfasst"}</td>
-                  <td className="px-5 py-4">
-                    <div className="flex justify-end gap-2">
-                      <button type="button" className="btn btn-secondary h-10 px-3" onClick={() => startEdit(item)}>Bearbeiten</button>
-                      <button type="button" className="btn btn-secondary h-10 px-3" onClick={() => resetMutation.mutate(item)}>{resetMutation.isPending ? <span className="spinner" /> : <RotateCcw className="h-4 w-4" />} Temporäres Passwort setzen</button>
-                      {item.is_active ? (
-                        <button type="button" className="btn btn-danger h-10 px-3" onClick={() => deactivateMutation.mutate(item)}>Deaktivieren</button>
-                      ) : (
-                        <button type="button" className="btn btn-success h-10 px-3" onClick={() => activateMutation.mutate(item)}><Check className="h-4 w-4" /> Reaktivieren</button>
-                      )}
-                    </div>
+              {!users.isLoading && !users.isError && (users.data?.items.length ?? 0) === 0 ? (
+                <tr>
+                  <td className="px-5 py-6 text-sm text-text-light" colSpan={7}>
+                    Keine Benutzer vorhanden.
                   </td>
                 </tr>
-              ))}
+              ) : (
+                (users.data?.items ?? []).map((item) => (
+                  <tr key={item.id}>
+                    <td className="px-5 py-4">{item.first_name} {item.last_name}</td>
+                    <td className="px-5 py-4">{item.email}</td>
+                    <td className="px-5 py-4">{roleLabels[item.role]}</td>
+                    <td className="px-5 py-4">{item.is_active ? "Aktiv" : "Inaktiv"}</td>
+                    <td className="px-5 py-4">{item.last_login_at ?? "nicht erfasst"}</td>
+                    <td className="px-5 py-4">{item.password_changed_at ?? "nicht erfasst"}</td>
+                    <td className="px-5 py-4">
+                      <div className="flex justify-end gap-2">
+                        <button type="button" className="btn btn-secondary h-10 px-3" onClick={() => startEdit(item)}>Bearbeiten</button>
+                        <button type="button" className="btn btn-secondary h-10 px-3" onClick={() => resetMutation.mutate(item)}>{resetMutation.isPending ? <span className="spinner" /> : <RotateCcw className="h-4 w-4" />} Passwort zurücksetzen</button>
+                        <button type="button" className="btn btn-danger h-10 px-3" onClick={() => setDeleteTarget(item)}><Trash2 className="h-4 w-4" /> Löschen</button>
+                      </div>
+                    </td>
+                  </tr>
+                ))
+              )}
             </tbody>
           </table>
         </div>
@@ -216,14 +247,29 @@ export default function UsersPage() {
         <span>{users.data?.total ?? 0} Datensätze</span>
         <div className="flex items-center gap-3">
           <button type="button" className="btn btn-secondary" disabled={page <= 1} onClick={() => setPage((v) => v - 1)}>Zurück</button>
-          <span>Seite {page}</span>
-          <button type="button" className="btn btn-secondary" disabled={(users.data?.items.length ?? 0) < 10} onClick={() => setPage((v) => v + 1)}>Weiter</button>
+          <span>Seite {page} von {pages}</span>
+          <button type="button" className="btn btn-secondary" disabled={(users.data?.items.length ?? 0) < 20 || page >= pages} onClick={() => setPage((v) => v + 1)}>Weiter</button>
         </div>
       </footer>
-      {temporaryPassword && <div className="fixed right-4 top-4 z-50 rounded-lg border border-success/30 bg-white p-4 shadow-soft"><p className="text-sm text-text-light">Temporäres Passwort</p><p className="mt-1 font-mono text-sm">{temporaryPassword}</p></div>}
+      {temporaryPasswordOpen && temporaryPassword && (
+        <div className="fixed inset-0 z-50 flex items-end bg-black/20 p-3 sm:items-center sm:justify-center">
+          <div className="w-full max-w-md rounded-lg border border-border bg-surface p-5 shadow-soft">
+            <div className="flex items-center justify-between gap-3">
+              <h2 className="text-lg font-semibold">Passwort zurückgesetzt</h2>
+              <button type="button" aria-label="Schliessen" onClick={() => setTemporaryPasswordOpen(false)} className="icon-btn"><X className="h-4 w-4" /></button>
+            </div>
+            <p className="mt-3 text-sm text-text-light">Dieses Passwort wird nur einmal angezeigt.</p>
+            <div className="mt-4 rounded-lg border border-border bg-background px-4 py-3 font-mono text-lg tracking-wide">{temporaryPassword}</div>
+            <div className="mt-4 flex flex-wrap gap-3">
+              <button type="button" className="btn btn-secondary h-11" onClick={async () => navigator.clipboard.writeText(temporaryPassword)}><Copy className="h-4 w-4" /> Kopieren</button>
+              <button type="button" className="btn btn-primary h-11" onClick={() => setTemporaryPasswordOpen(false)}>Schliessen</button>
+            </div>
+          </div>
+        </div>
+      )}
       {message && <div className="fixed right-4 top-4 z-50 rounded-lg border border-success/30 bg-white p-4 text-sm text-success shadow-soft">{message}</div>}
       {error && <div className="fixed right-4 top-4 z-50 rounded-lg border border-danger/30 bg-white p-4 text-sm text-danger shadow-soft">{error}</div>}
-      <form onSubmit={form.handleSubmit((values) => saveMutation.mutate(values))} className="rounded-lg border border-border bg-surface p-5 shadow-soft">
+      <form onSubmit={form.handleSubmit(submit)} className="rounded-lg border border-border bg-surface p-5 shadow-soft">
         <h2 className="text-xl font-semibold">{editing ? "Benutzer bearbeiten" : "Benutzer anlegen"}</h2>
         <div className="mt-4 grid gap-4 md:grid-cols-2">
           {(["first_name", "last_name", "email", "temporary_password"] as const).map((field) => (
@@ -243,9 +289,28 @@ export default function UsersPage() {
         </div>
         <div className="mt-5 flex justify-end gap-3">
           <button type="button" className="btn btn-secondary" onClick={() => form.reset()}>Zurücksetzen</button>
-          <button type="submit" className="btn btn-primary">{saveMutation.isPending ? <span className="spinner" /> : null} Speichern</button>
+          <button type="submit" disabled={saveMutation.isPending} className="btn btn-primary">{saveMutation.isPending ? <span className="spinner" /> : null}{saveMutation.isPending ? "Speichern..." : "Speichern"}</button>
         </div>
       </form>
+      {deleteTarget && (
+        <div className="fixed inset-0 z-50 flex items-end bg-black/20 p-3 sm:items-center sm:justify-center">
+          <div className="w-full max-w-lg rounded-lg border border-border bg-surface p-5 shadow-soft">
+            <h2 className="text-xl font-semibold">Benutzer wirklich löschen?</h2>
+            <p className="mt-2 text-sm text-text-light">
+              {deleteTarget.first_name} {deleteTarget.last_name}
+              <br />
+              {deleteTarget.email}
+            </p>
+            <div className="mt-5 flex justify-end gap-3">
+              <button type="button" className="btn btn-secondary" onClick={() => setDeleteTarget(null)}>Abbrechen</button>
+              <button type="button" className="btn btn-danger" disabled={deleteMutation.isPending} onClick={() => deleteMutation.mutate(deleteTarget)}>
+                {deleteMutation.isPending ? <span className="spinner" /> : null}
+                {deleteMutation.isPending ? "Löschen..." : "Löschen"}
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
     </div>
   );
 }
diff --git a/validation-suite/frontend/atlas/app/(app)/validations/quick-start/page.tsx b/validation-suite/frontend/atlas/app/(app)/validations/quick-start/page.tsx
new file mode 100644
index 00000000..443f7c7e
--- /dev/null
+++ b/validation-suite/frontend/atlas/app/(app)/validations/quick-start/page.tsx
@@ -0,0 +1,24 @@
+"use client";
+
+import Link from "next/link";
+import ValidationEditor from "@/components/validations/validation-editor";
+
+export default function QuickStartValidationPage() {
+  return (
+    <div className="space-y-6">
+      <header className="rounded-lg border border-border bg-surface p-6 shadow-soft">
+        <p className="text-sm font-medium uppercase tracking-wide text-primary">Schnellstart</p>
+        <h1 className="mt-2 text-3xl font-semibold text-text">Neue Validierung starten</h1>
+        <p className="mt-2 max-w-3xl text-text-light">
+          Wir arbeiten die Validierung direkt auf einer Seite durch und ziehen vorhandene Daten sofort nach.
+        </p>
+        <div className="mt-5">
+          <Link className="btn btn-secondary" href="/validations">
+            Zur Validierungsübersicht
+          </Link>
+        </div>
+      </header>
+      <ValidationEditor />
+    </div>
+  );
+}
diff --git a/validation-suite/frontend/atlas/lib/api.ts b/validation-suite/frontend/atlas/lib/api.ts
index 822c50b0..9e283053 100644
--- a/validation-suite/frontend/atlas/lib/api.ts
+++ b/validation-suite/frontend/atlas/lib/api.ts
@@ -118,8 +118,22 @@ export type Paginated<T> = {
   total: number;
   page: number;
   page_size: number;
+  pages?: number;
 };
 
+async function readErrorMessage(response: Response, fallback: string) {
+  const text = await response.text();
+  if (!text) {
+    return fallback;
+  }
+  try {
+    const parsed = JSON.parse(text) as { detail?: string; message?: string };
+    return parsed.detail ?? parsed.message ?? text;
+  } catch {
+    return text;
+  }
+}
+
 export async function login(email: string, password: string) {
   const response = await fetch(`/api/login`, {
     method: "POST",
@@ -155,8 +169,7 @@ export async function apiSend<T>(path: string, token: string, method: "POST" | "
     credentials: "include"
   });
   if (!response.ok) {
-    const detail = await response.text();
-    throw new Error(detail || `API request failed: ${response.status}`);
+    throw new Error(await readErrorMessage(response, `API request failed: ${response.status}`));
   }
   return response.json() as Promise<T>;
 }
@@ -167,7 +180,7 @@ export async function apiDelete(path: string, token: string): Promise<void> {
     credentials: "include"
   });
   if (!response.ok) {
-    throw new Error(`API request failed: ${response.status}`);
+    throw new Error(await readErrorMessage(response, `API request failed: ${response.status}`));
   }
 }
 
@@ -178,7 +191,7 @@ export async function apiFetch<T>(path: string, token: string, init?: RequestIni
     credentials: "include"
   });
   if (!response.ok) {
-    throw new Error(await response.text());
+    throw new Error(await readErrorMessage(response, `API request failed: ${response.status}`));
   }
   return response.json() as Promise<T>;
 }
diff --git a/validation-suite/frontend/atlas/lib/users-query.d.ts b/validation-suite/frontend/atlas/lib/users-query.d.ts
new file mode 100644
index 00000000..b7d8beec
--- /dev/null
+++ b/validation-suite/frontend/atlas/lib/users-query.d.ts
@@ -0,0 +1,9 @@
+export function buildUsersQueryParams(input: {
+  page: number;
+  pageSize: number;
+  search?: string;
+  role?: string;
+  active?: boolean | null;
+  sortBy: string;
+  sortOrder: "asc" | "desc";
+}): URLSearchParams;
diff --git a/validation-suite/frontend/atlas/lib/users-query.js b/validation-suite/frontend/atlas/lib/users-query.js
new file mode 100644
index 00000000..710e4295
--- /dev/null
+++ b/validation-suite/frontend/atlas/lib/users-query.js
@@ -0,0 +1,18 @@
+export function buildUsersQueryParams({ page, pageSize, search, role, active, sortBy, sortOrder }) {
+  const params = new URLSearchParams({
+    page: String(page),
+    page_size: String(pageSize),
+    sort_by: sortBy,
+    sort_order: sortOrder
+  });
+  if (search && search.trim()) {
+    params.set("search", search.trim());
+  }
+  if (role) {
+    params.set("role", role);
+  }
+  if (active === true || active === false) {
+    params.set("active", String(active));
+  }
+  return params;
+}
diff --git a/validation-suite/frontend/atlas/package.json b/validation-suite/frontend/atlas/package.json
index 3df8c45f..720a225c 100644
--- a/validation-suite/frontend/atlas/package.json
+++ b/validation-suite/frontend/atlas/package.json
@@ -7,7 +7,8 @@
     "build": "next build",
     "start": "next start",
     "lint": "next lint",
-    "test:auth": "node --test tests/auth-cookie.test.mjs"
+    "test:auth": "node --test tests/auth-cookie.test.mjs",
+    "test:users-query": "node --test tests/users-query.test.mjs"
   },
   "dependencies": {
     "@hookform/resolvers": "^3.10.0",
diff --git a/validation-suite/frontend/atlas/tests/users-query.test.mjs b/validation-suite/frontend/atlas/tests/users-query.test.mjs
new file mode 100644
index 00000000..af799d6b
--- /dev/null
+++ b/validation-suite/frontend/atlas/tests/users-query.test.mjs
@@ -0,0 +1,42 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { buildUsersQueryParams } from "../lib/users-query.js";
+
+test("builds query without empty optional filters", () => {
+  const params = buildUsersQueryParams({
+    page: 1,
+    pageSize: 20,
+    search: "",
+    role: "",
+    active: undefined,
+    sortBy: "created_at",
+    sortOrder: "desc"
+  });
+
+  assert.equal(params.toString(), "page=1&page_size=20&sort_by=created_at&sort_order=desc");
+});
+
+test("builds query with active filters", () => {
+  const activeParams = buildUsersQueryParams({
+    page: 1,
+    pageSize: 20,
+    search: "  Admin  ",
+    role: "admin",
+    active: true,
+    sortBy: "created_at",
+    sortOrder: "desc"
+  });
+
+  const inactiveParams = buildUsersQueryParams({
+    page: 1,
+    pageSize: 20,
+    search: "",
+    role: "",
+    active: false,
+    sortBy: "created_at",
+    sortOrder: "desc"
+  });
+
+  assert.equal(activeParams.toString(), "page=1&page_size=20&sort_by=created_at&sort_order=desc&search=Admin&role=admin&active=true");
+  assert.equal(inactiveParams.toString(), "page=1&page_size=20&sort_by=created_at&sort_order=desc&active=false");
+});