diff --git a/backend/app/modules/project/application/services.py b/backend/app/modules/project/application/services.py
index e69de29..2e9ae9b 100644
--- a/backend/app/modules/project/application/services.py
+++ b/backend/app/modules/project/application/services.py
@@ -0,0 +1,42 @@
+import uuid
+from datetime import datetime, timezone
+from pathlib import Path
+
+from app.modules.project.domain.entities import Project
+from app.modules.project.domain.repositories import ProjectRepository
+from app.shared.kernel.exceptions import NotFoundError, ValidationError
+
+
+class ProjectService:
+    def __init__(self, repository: ProjectRepository) -> None:
+        self._repo = repository
+
+    def list_projects(self) -> list[Project]:
+        return self._repo.list_all()
+
+    def create_project(
+        self, name: str, design_dir: str, code_dir: str | None = None,
+    ) -> Project:
+        if not Path(design_dir).is_dir():
+            raise ValidationError(f"Design directory does not exist: {design_dir}")
+        project = Project(
+            id=str(uuid.uuid4()),
+            name=name,
+            design_dir=design_dir,
+            code_dir=code_dir,
+            created_at=datetime.now(timezone.utc),
+        )
+        self._repo.save(project)
+        return project
+
+    def get_project(self, project_id: str) -> Project:
+        project = self._repo.get_by_id(project_id)
+        if project is None:
+            raise NotFoundError("Project", project_id)
+        return project
+
+    def delete_project(self, project_id: str) -> None:
+        project = self._repo.get_by_id(project_id)
+        if project is None:
+            raise NotFoundError("Project", project_id)
+        self._repo.delete(project_id)
diff --git a/backend/tests/test_project.py b/backend/tests/test_project.py
index bc93340..8af535a 100644
--- a/backend/tests/test_project.py
+++ b/backend/tests/test_project.py
@@ -42,3 +42,42 @@ def test_delete(repo: JsonProjectRepository):
 
 def test_get_nonexistent_returns_none(repo: JsonProjectRepository):
     assert repo.get_by_id("nope") is None
+
+
+# --- Service tests ---
+
+from app.modules.project.application.services import ProjectService
+from app.shared.kernel.exceptions import NotFoundError, ValidationError
+
+
+@pytest.fixture
+def service(tmp_path: Path) -> ProjectService:
+    repo = JsonProjectRepository(tmp_path / "projects.json")
+    return ProjectService(repo)
+
+
+def test_create_project_validates_design_dir(service: ProjectService, tmp_path: Path):
+    design_dir = tmp_path / "design"
+    design_dir.mkdir()
+    project = service.create_project("test", str(design_dir))
+    assert project.name == "test"
+    assert project.id  # UUID generated
+
+
+def test_create_project_rejects_missing_dir(service: ProjectService):
+    with pytest.raises(ValidationError):
+        service.create_project("test", "/nonexistent/path")
+
+
+def test_get_project_not_found(service: ProjectService):
+    with pytest.raises(NotFoundError):
+        service.get_project("nonexistent")
+
+
+def test_delete_project(service: ProjectService, tmp_path: Path):
+    design_dir = tmp_path / "design"
+    design_dir.mkdir()
+    p = service.create_project("test", str(design_dir))
+    service.delete_project(p.id)
+    with pytest.raises(NotFoundError):
+        service.get_project(p.id)