Performance Aider Conventions

- Define performance budgets before building: max response time, max bundle size
- Measure first: never optimize code without a benchmark proving the bottleneck
- Cache invalidation strategy must be defined before implementing any cache
- Log slow operations: queries > 100ms, HTTP calls > 500ms at WARNING level
- Use lazy loading for all non-critical code, images, and modules
- Implement request timeouts on all external dependencies
- Use CDN for static assets; set immutable cache headers for hashed assets
- Monitor P95 and P99 latency, not just averages; averages hide tail latency