There's a good post making the rounds — "RAG for Codebases Is Harder Than It Looks" — on why naive retrieval falls apart on code. Filtering out node_modules, chunking on AST boundaries instead of token counts, preserving file-path metadata, treating architecture questions as graph traversals rather than nearest-neighbor lookups. All correct. If you're building code RAG, read it.
But notice where the author lands at the very end:
Developer trust depends on retrieval quality, honest uncertainty acknowledgment, and verifiable sources — not just algorithmic sophistication.
That's the part I want to pull on. Because everything before it — better chunking, better embeddings, repo maps — makes the model's answer more likely to be right. None of it makes the answer checkable. And once an LLM is writing your code, "more likely to be right" is not the same problem as "did it actually do what it just told me it did."
The retrieval is upstream of a bigger trust gap
