At the begining of the project, the runs are fast, but as the project gets bigger, the runs are slower:
- there are bigger contexts
- the test suite is much longer and slower
- you need to split worktree, resources (like db, ports) and sometimes containers to work in isolation
So having 10 workers will run for a long time. Which give plenty of time to write good spec.
You need good spec, so the llm produce good tests, so it can write good code to match these tests.
Having a very strong spec + test suite + quality gates (linter, type checkers, etc) is the only way to get good results from an LLM as the project become more complex.
Unlike a human, it's not very good at isolating complexity by itself, nor stopping and asking question in the face of ambiguity. So the guardrails are the only thing that keeps it on track.
And running a lot of guardrail takes time.
E.G: yesterday I had a big migration to do from HTMX to viewjs, I asked the LLM to produce screenshots of each state, and then do the migration in steps in a way that kept the screenshit 90% identical.
This way I knew it would not break the design.
But it's very long to run e2e tests + screenshot comparison every time you do a modification. Still faster than a human, but it gives plenty of time to talk to another llm.
Plus you can assign them very different task:
- One work on adding a new feature
- One improves the design
- One refactor part of the code (it's something you should do regularly, LLM produce tech debt quickly)
- One add more test to your test suite
- One is deploying on a new server
- One is analyzing the logs of your dev/test/prod server and tell you what's up
- One is cooking up a new logo for you and generating x versions at different resolutions.
Etc.
It's basically a small team at your disposal.