Design retrieval for a coding agent over a code base

A coding agent is an LLM assistant that works inside a software code base: it reads code, answers questions about it and makes edits. It depends on retrieval to put the right code and documentation into its context window.

Design that retrieval layer. Cover what you index and how you split it into pieces, how you keep noisy or irrelevant results out of the context, and which metrics tell you retrieval is working.