Backend Design Skill

This skill guides the design of reliable backend systems, APIs, and data models with clear trade-offs, strong correctness guarantees, and operational readiness.

Design Thinking

• Scope: Identify core use cases, data flows, and integration points.

• Constraints: Latency, throughput, availability, compliance, and deployment limits.

• Data: Define entities, relationships, invariants, and lifecycle.

• Reliability: Error handling, retries, idempotency, and consistency model.

Architecture Guidelines

• API Design: Explicit contracts, versioning, validation, and error shape.

• Storage: Choose stores based on access patterns and durability needs.

• Performance: Indexing, caching, batching, and async processing.

• Security: AuthN/AuthZ, least privilege, secrets handling, auditability.

• Observability: Logging, metrics, tracing, and alerting signals.

• Scalability: Stateless services where possible, clear scaling boundaries.

Output Requirements

Provide a clear backend plan or implementation that includes:

• Data model and key invariants

• API endpoints or service interfaces

• Failure modes and recovery strategy

• Performance and scaling considerations

• Security and observability notes

Response Checklist

Backend Design Checklist

• Confirm requirements and constraints
• Define data model and invariants
• Specify API contracts and error shape
• Address failure modes and consistency
• Cover performance, scaling, and caching
• Include security and observability plans