Agent skill · software engineering · addyosmani
performance-optimization
Optimizes application performance across frontend, backend, queries, and databases. Use when performance requirements exist, when you suspect performance regressions, when Core Web Vitals or load times need improvement, when N+1 query patterns need fixing, or when profiling reveals bottlenecks.
Why this skill is useful
Provides specific performance optimization techniques and profiling commands that the AI wouldn't reliably generate on its own.
What it needs
Requires lighthouse, web-vitals installed locally. About 12k tokens when loaded. Last updated 2026-08-06. 83,053 stars on the source repository.
What this skill does
Performance Optimization Overview Measure before optimizing. Performance work without measurement is guessing — and guessing leads to premature optimization that adds complexity without improving what matters. Profile first, identify the actual bottleneck, fix it, measure again. Optimize only what measurements prove matters. When to Use Performance requirements exist in the spec (load time budgets, response time SLAs) Users or monitoring report slow behavior Core Web Vitals scores are below thresholds You suspect a change introduced a regression Building features that handle large datasets or high traffic When NOT to use: Don't optimize before you have evidence of a problem. Premature optimization adds complexity that costs more than the performance it gains. Core Web Vitals Targets Metric Good Needs Improvement Poor -------- ------ ------------------- ------ LCP (Largest Contentful Paint) ≤ 2.5s ≤ 4.0s > 4.0s INP (Interaction to Next Paint) ≤ 200ms ≤ 500ms > 500ms CLS (Cumulative Layout Shift) ≤ 0.1 ≤ 0.25 > 0.25 The Optimization Workflow Step 1: Measure Two complementary approaches — use both: Synthetic (Lighthouse, DevTools Performance tab): Controlled conditions, reproducible. Best for CI regression detection and isolating specific issues. RUM (web-vitals library, CrUX): Real user data in real conditions. Required to validate that a fix actually improved user experience. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills addyosmani/performance-optimization