Go Performance

Start with measurement, not rewriting.

When to use this skill

• Profile Go code with pprof, runtime/trace, flight recording, or IDE-collected pprof-compatible profiles.
• Diagnose CPU hot paths, allocation pressure, retained heap growth, goroutine pileups, scheduler delay, or lock/channel contention.
• Write or repair Go benchmarks and compare performance changes with benchstat.
• Decide whether a measured Go optimization is worth the added complexity.

When NOT to use this skill

• No measurement of an actual performance problem exists yet. Write the benchmark or capture the profile first; do not optimize speculatively.
• The task is correctness, refactoring, or API design without a throughput, latency, or resource concern.
• The user wants a Go language tutorial or general code review, not performance work.

Read the right reference