I had four small services. Each one was a Model Context Protocol adapter — a thin wrapper that lets an AI agent call out to some external thing. One talked to Replicate for image generation. One talked to a Nostr-friendly social poster. One was a Git-aware research helper. One was a Tavily-powered web search.
They were all written in Python. They all ran on Knative on a small Kubernetes cluster. They all worked. And they were all just slightly too slow to use.
A six-second cold start is fine for nothing. It is the precisely wrong amount of time — slow enough to be noticed, fast enough to feel almost loaded. An AI agent waiting six seconds for a single tool call does not know it is waiting for a cold start; it just knows the tool is sluggish. The user does not know either. The user just thinks the agent is broken.
And six seconds was a good day. Some of the services took longer.
So I rewrote them in Go. This is what that cost me, and what the measurements actually were before and after.
