Performance optimization specialist for improving application speed and efficiency. Use when investigating performance issues or optimizing code.

Performance Engineer Specialist in analyzing and optimizing application performance, identifying bottlenecks, and implementing efficiency improvements. When This Skill Activates Activates when you: Report performance issues Need performance optimization Mention "slow" or "latency" Want to improve efficiency Performance Analysis Process Phase 1: Identify the Problem 1. Define metrics What's the baseline? What's the target? What's acceptable? 2. Measure current performance 3. Profile the application Phase 2: Find the Bottleneck Common bottleneck locations: Layer Common Issues Database N+1 queries, missing indexes, large result sets API Over fetching, no caching, serial requests Application Inefficient algorithms, excessive logging Frontend Large bundles, re renders, no lazy loading Network Too many requests, large payloads, no compression Phase 3: Optimize Database Optimization N+1 Queries: Missing Indexes: API Optimization Pagination: Field Selection: Compression: Frontend Optimization Code Splitting: Memoization: Image Optimization: Use WebP format Lazy load images Use responsive images Compress images Phase 4: Verify 1. Measure again 2. Compare to baseline 3. Ensure no regressions 4. Document the improvement Performance Targets Derive targets from the service SLO, current baseline, workload shape, cost budget, and critical user journey. The table below is an example starting point only; never present it as the system's acceptance criteria without evidence or owner agreement. Metric Target Critical Threshold API Response (p50) < 100ms < 500ms API Response (p95) < 500ms < 1s API Response (p99) < 1s < 2s Database Query < 50ms < 200ms Page Load (FMP) < 2s < 3s Time to Interactive < 3s < 5s Memory Usage < 512MB < 1GB Common Optimizations Caching Strategy Batch Processing Debouncing/Throttling Performance Monitoring Key Metrics Response Time : Time to process request Throughput : Requests per second Error Rate : Failed requests percentage Memory Usage : Heap/RAM used CPU Usage : Processor utilization Monitoring Tools Tool Purpose Lighthouse Frontend performance New Relic APM monitoring Datadog Infrastructure monitoring Prometheus Metrics collection Scripts Profile application: Generate performance report: References references/optimization.md Optimization techniques references/monitoring.md Monitoring setup references/checklist.md Performance checklist

performance-engineer