I Replaced My Dev Team With AI Agents for a Week. Here's What Actually Shipped.

For one week I gave the week's backlog to five AI agents instead of five engineers, and I kept score. Not a hackathon toy — the real board, the real repo, the real merge button. Here is the honest tally before I tell you what it means: 23 PRs opened by agents 14 merged 3 reverted within 48h 1 near-miss: an agent "cleaned up" a migration and nearly dropped a staging table 6 still open, waiting on a human decision they couldn't make That is not a disaster and it is not a miracle. It is the most useful week of data I have collected on where this actually works, so let me be specific instead of vibes. The setup Five agents, each with a narrow job, wired to the repo and CI: a decomposer that turned each ticket into a task list and acceptance criteria a backend agent and a frontend agent that did the actual work a test agent that only wrote and ran tests, nothing else a reviewer agent that read every diff before it reached me The rule: no agent could merge. Every PR still landed on me. I wanted to measure the agents, not hand them the keys. What shipped, and why it shipped The 14 that merged were almost all the same shape of work: CRUD endpoints with a clear schema a data migration with a written spec test coverage for code that already existed dependency bumps and the small breakages they caused a boring, well-defined refactor across 30 files Notice the pattern. Everything that shipped was work where the hard part was typing, not deciding. When the spec was unambiguous, the agents were faster than my team and they did not get bored on file 27 of 30, which is exactly where humans introduce the typo. The test agent was the surprise MVP. It wrote the tests we had been "getting to" for six months. It had no ego about it and no better idea to pitch. It just wrote the tests. What broke, and why it broke The 3 reverts and the near-miss all share a shape too: The migration cleanup assumed it understood why a column was nullable. It wasn't; a nightly job depended on the null. Individually every line the agent wrote was correct. The decision was wrong, and nothing in the diff looked wrong. A "small" auth change touched a permission check the agent couldn't see the blast radius of. It passed review — the reviewer agent also couldn't see the blast radius. Two reverts were the same bug: the agent optimized a function into something faster and subtly wrong, and the tests it wrote passed because it wrote them to match its own wrong mental model. That last one is the whole game. An agent that writes both the code and the tests will make them agree with each other, not with reality. This is not a model-quality problem you wait out. It is structural, and it is why the test agent had to be a different agent from the one writing the code. The thing that got twice as hard Here is the part nobody puts in the thread. I did not save a week of work. I moved it. The bottleneck left "writing the code" and reappeared, larger, in two places: Specification. The 6 PRs that stalled didn't stall because the agents were dumb. They stalled because the ticket was a sentence a human teammate would have interpreted with context the agent didn't have. Underspecified work doesn't get done badly by an agent — it gets done confidently and wrongly, which is worse. Review. 23 PRs is a lot of reading. Reviewing code you didn't write, that looks plausible everywhere, with the bugs living in the decisions rather than the syntax — that is slower and more tiring per line than reviewing a human's work, because a human's diff carries their intent and an agent's carries only its output. By Thursday I understood the real trade. Agents didn't replace my engineers. They replaced the fast, low-judgment middle of the work and handed me back a job that is almost entirely spec-writing and judgment — the two things I was worst at making time for. What I actually kept After the week I did not fire anyone and I did not turn the agents off. I changed what they're pointed at: Agents own the well-specified, high-typing, low-judgment work. Migrations with a written plan. Test backfill. Mechanical refactors. The boring 80%. Humans own the spec going in and the judgment coming out — and now have the hours to, because the boring 80% stopped eating them. Code and tests are never written by the same agent. Ever. Nothing an agent writes merges without a human who can see the blast radius the agent can't. The honest headline isn't "AI replaced my dev team." It's: AI deleted the part of the job that felt like work, and left me the part that is the actual work. Whether that's a threat or a gift depends entirely on whether you were adding value in the typing or in the deciding. I ran this on xenition — the agent platform we build — because "dogfood your own agents on your own backlog" is the only benchmark I trust. The tally above is from one real week; your mileage will move with how well your tickets are written, which turns out to be the whole point. What's the smallest, most boring task on your board right now? That's the one to hand over first. Tell me in the comments what broke when you did.