> now LLMs just buzz through the file changing thousands of lines and we can't keep up. It's still valuable to deeply understand parts of a program, but we don't have any tooling that helps us do that.

I do it differently, I focus on better recording what the user wanted, the so-called "user intent". To do this, I record all messages typed by the user since the start of the project, whether 3,000 or 10,000 messages. An LLM can churn through them in 10 minutes and derive a fresh, up-to-date interpretation from the raw data. This can be used to judge whether the implementation has diverged from the intent, or, in other words, to realign the code and tests. The messages the user writes are usually designs or corrections, a very rich, compact signal. If the user struggles with something, it could result in a tool, a skill, updates to the project docs, or new tests.