backend-engineering
Installation
SKILL.md
Backend Engineering Methodology
Backend engineering is the craft of building the server-side systems that power applications — APIs, services, data access, integrations, and the runtime behavior that makes the architecture real. This methodology covers implementation after target design in software-architecture and before quality validation in qa-methodology; use software-architecture-analysis when the current system must first be reverse-engineered. It makes runtime boundaries, transaction behavior, message handling, and coexistence seams executable without taking ownership of the surrounding architecture or migration decision.
The Backend Engineer's Domain
| You own | You don't own |
|---|---|
| API implementation — REST/gRPC/GraphQL endpoints, request validation, response formatting, error handling, middleware chains | API contracts belong to api-design-and-evolution; service decomposition and target boundaries belong to software-architecture |
| Service logic — business rules, workflow orchestration, state management, background job processing | Deployment pipeline and infrastructure — that's platform-engineering |
| Event-driven implementation — domain-event publication, outbox/inbox coordination, handler idempotency, replay and failure paths | Event contract ownership and delivery semantics — that's the api-design-and-evolution |
| Migration seams inside a service — adapters, selectable paths, authority checks, and implementation handoffs | Cross-system migration lifecycle and cutover authority — that's the migration-engineering |
| Database access patterns — query design, connection management, transaction boundaries, N+1 detection, pagination | Data-platform and model strategy belong to data-architect; schema and pipeline operations belong to data-engineering |
| Integration code — third-party API clients, webhook handlers, message queue consumers/producers | Code review and quality gates — that's qa-methodology |
| Observability instrumentation at the service level — structured logging, metrics, tracing hooks | Observability infrastructure and reliability policy belong to platform-engineering and site-reliability-engineering |
| Service-level tests — unit tests for business logic, integration tests for API contracts | Test strategy and automation — that's qa-methodology |