2 posts tagged with "monorepo"

A team I worked with recently had three different "summarize this contract" prompts. One lived in a Notion page that the legal-tech squad copy-pasted into their service. One lived in a prompts/ folder in the customer-success backend, slightly modified to handle their tone preferences. One lived inline in a Python file inside the data team's notebook, hardcoded between two f-string interpolations. When OpenAI deprecated the model they all ran on, the migration plan involved Slack archaeology — each owner had to be tracked down, each variant had to be re-evaluated, and two of the three subtly broke in production for a week before anyone noticed.

This is what a prompt cookbook looks like at scale. Cookbooks make sense for ten prompts and one team. They become unmanageable somewhere around a hundred prompts and four teams. By the time you're running an AI organization, your prompts/ folder of .md files behaves exactly like vendored copy-paste code from 2008: every consumer has its own snapshot, drift is invisible, and breaking changes ripple outward in unpredictable ways.

Here's a failure mode that happens silently: you ask a coding agent to update the authentication service's token refresh endpoint. The agent produces clean-looking code — confident, well-commented, type-safe. It also calls a method signature that was renamed three months ago in a shared library three directories up. The tests for that endpoint pass because the mock still uses the old signature. The bug surfaces in staging when the real library gets pulled in.

This isn't a hallucination in the abstract sense. The model knew about that method — it existed somewhere in the training data or was briefly visible in context. The problem is architectural: the agent never had access to the current version of the interface it was calling.