Latency Critical Systems Use this skill when the user cares about realtime behavior, hot paths, streaming freshness, or execution speed. This includes HFT-like infrastructure, but the skill is engineering-focused. It does not authorize live trading or financial advice. Split The Metrics Do not collapse everything into "fast." Track: - p50, p95, and p99 latency; - throughput; - freshness age; - queue depth; - cache hit rate; - provider/API response time; - browser render time; - correctness under load; - failure and retry behavior. Map The Hot Path Write the path from user/event to final visib…