backend-data

# Backend & Data Layer 2 domain skill for all server-side development and data persistence. Routes to reference files and Layer 3 atomic skills by task type. ## Task Router | Task Pattern | Reference | Layer 3 Skills | |---|---|---| | REST API design, URL structure, status codes | `references/rest-graphql.md` | — | | GraphQL schema, resolvers, DataLoader | `references/rest-graphql.md` | — | | Node.js, Express, Fastify, middleware | `references/nodejs-patterns.md` | — | | SQL optimization, EXPLAIN, query tuning | `references/sql-optimization.md` | — | | ORM (Prisma, Drizzle, TypeORM, SQLAlchemy) | `references/orm-patterns.md` | — | | API auth, JWT, OAuth, rate limiting | `references/api-security.md` | security-deep, auth-clerk | | Microservices, message queues, Kafka, RabbitMQ | `references/microservices.md` | — | | Database migrations, schema changes | `references/migrations.md` | — | | Data modeling, normalization, schema design | `references/data-modeling.md` | — | | Webhooks, signatures, idempotency | `references/webhooks.md` | — | ## When to Use Activate for any task involving: - API design or implementation (REST, GraphQL, gRPC) - Database queries, schema design, or migrations - Authentication and authorization patterns - Server-side Node.js with Express or Fastify - Microservices architecture or message queues - Caching strategies (Redis) - Webhook implementation or consumption ## Layer 3 Skills (Atomic) - **db-convex** — Convex database operations and schema management - **db-supabase** — Supabase database operations - **auth-clerk** — Authentication with Clerk - **payments-stripe** — Stripe payment integration ## Quick Decision Trees ### Protocol Choice ``` Service-to-service, high throughput? → gRPC Flexible client queries, nested data? → GraphQL Simple CRUD, broad tooling? → REST (default) ``` ### Database Choice ``` Default → PostgreSQL (JSONB, full-text search, pgvector) Embedded/local-first → SQLite (WAL mode) Caching/sessions → Redis Document store, evolving schema → MongoDB AWS-native, single-digit ms → DynamoDB ``` ### ORM Choice ``` TypeScript, great DX? → Prisma (schema-first) TypeScript, SQL-like syntax? → Drizzle (lighter) Python? → SQLAlchemy Complex raw SQL needs? → Drop to query builder ```