what i actually learned coordinating 15 MCP servers (it's not what you'd expect)

everyone talks about MCP servers like they're the hard part. they're not. writing a single MCP server is maybe 200 lines of code. the hard part is what happens when you have 15 of them running simultaneously and they all need to cooperate. i've been building a multi-agent system for the past few months. 9 services, 15 MCP servers, 60+ Cloudflare Workers. here's what i actually learned — most of it the hard way. lesson 1: the orchestration layer is the real product anyone can write an MCP server. child_process.exec() , parse the output, return JSON. done. but when server #7 times out and server #3 depends on its output, and server #12 is rate-limited, and the user is waiting... that's where the real engineering lives. we built a coordinator daemon that does health checks every 30 seconds across all services. when something goes down, it doesn't just retry — it reroutes through fallback chains. primary fails? try the secondary. secondary fails? degrade gracefully and tell the user what h