data-conventions

Loading Conventions

Project-level conventions are loaded automatically via .claude/skills/backend-conventions.md when editing services/**/*.cs or shared/**/*.cs files. Data engineers follow the same backend patterns.

If project-level skills are not available (e.g., older branch), read these files directly:

• docs/CODING_STYLE_BACKEND.md
• docs/API_CONVENTIONS.md
• docs/TESTING_GUIDELINES_BACKEND.md

DTF Supplements for Data Work

EF Core Migrations

• Consolidate corrective migrations into a single clean migration before merging.
• Use dotnet ef migrations remove and re-add, never edit migration files by hand.
• Always add a data migration when removing or renaming a persisted enum value.
• No regression tests needed for data-only migrations.

Query Patterns

• Avoid N+1: never execute queries inside loops. Fetch all data in one query, process in memory.
• Materialize IEnumerable with ToList() before multiple iteration.
• Use database constraints or upsert (ON CONFLICT) instead of check-then-act patterns.
• Pass CancellationToken through call chains for long-running operations.

Seed Data

• When adding new tables or schema changes, always add seed data.
• Check the GitHub bot reminder on PRs — it flags missing seed data.