Why Your Go Service Has Latency Spikes (Even If It’s “Fast”)

You shipped a Go service. Benchmarks look great. CPU usage is low. Average latency is comfortably within targets. And yet every now and then your p99 explodes. This is the part many engineers underestimate: fast systems can still be unpredictable systems . In Go, latency spikes are rarely caused by a single obvious bottleneck. They emerge from the interaction between the runtime, the OS, and your code under real-world load. Let’s dig into the less obvious reasons your Go service spikes and what