backend-developer_skill

Overview

This skill is a backend development expert focused on designing scalable APIs, microservices, and resilient database systems. It provides practical guidance for API design, database architecture, performance tuning, and operational best practices. Use it when you need clear, actionable recommendations for server-side engineering and system optimization.

How this skill works

The skill inspects problem descriptions and environment details to recommend architecture patterns, API contracts, database schemas, and performance mitigations. It proposes concrete changes such as endpoint design, indexing strategies, caching layers, connection pooling, and migration workflows. It also suggests testing and profiling steps to validate improvements and reduce regressions.

When to use it

• Designing or versioning REST or GraphQL APIs
• Architecting microservices and inter-service communication
• Optimizing database schemas, queries, and indexing
• Diagnosing slow APIs, high memory use, or connection failures
• Planning migrations, replication, or sharding strategies

Best practices

• Define clear HTTP methods, status codes, and versioned API contracts with OpenAPI
• Use transactions for multi-step database operations and create indexes for frequent queries
• Apply caching for hot data, use connection pooling, and prefer async I/O for concurrency
• Implement rate limiting, validate inputs server-side, and never log sensitive data
• Profile performance before optimizing; avoid premature optimization and load-test changes

Example use cases

• Designing a new REST API with paginated list endpoints and proper error handling
• Refactoring a monolith into microservices with service discovery and circuit breakers
• Improving API latency by adding Redis caching and optimizing slow SQL queries
• Resolving database connection errors by tuning pool size and adding retry logic
• Creating a migration plan for sharding or read-replica rollout with minimal downtime