We Replaced Hours of Manual API Testing With an AI Agent Running Integration Tests in Real Time

— and it didn't just write the tests. It debugged Kubernetes RBAC, fixed race conditions, and shipped all 40 passing. Let me tell you what happened this week, because I think it signals something real about where developer workflows are heading. I'm building a PaaS that lets you deploy MCP (Model Context Protocol) servers on Kubernetes with a single API call. This week we shipped a new feature branch: replica management — the ability to start, stop, restart, and scale running MCP servers. Standard stuff. But the way we tested it was anything but. The Old Way: Postman (and Why It Slows You Down) Most backend engineers know the drill. You open Postman. You find the right collection. You manually update the Authorization header with a freshly copied token. You click Send on the first endpoint, copy an ID from the response, paste it into the next request, click Send again. You spend 20 minutes setting up a flow that tests 5 endpoints in sequence — not because the logic is hard, but because