Multi-agent engineering with Claude Code: the dev loop, demonstrated
The previous post walked through a single Claude Code session — one engineer, one context window, 14 turns. That's the right shape for most work. But some tasks don't fit in one brain. A migration across 12 services, a security audit of 200 endpoints, a refactor that touches every file in the repo — these want a small team, not one engineer working 14-hour days.
Claude Code has a Task tool that spawns sub-agents with isolated context windows. The main session is the lead engineer; sub-agents are specialists. Each specialist runs to completion, returns a summary, and the lead stitches the work together. That's the multi-agent loop, in Claude Code.
This post is a full session that uses it. I'll do a real task — port a Python CLI from one config library to another across 8 files — by having Claude Code delegate parts to sub-agents. You'll see the prompts, the sub-agent invocations, where handoffs went well, and where they didn't.
The session is reconstructed from real Claude Code runs. The patterns work; the exact transcripts are illustrative.
