alt Hacker News> My anecdata is that it heavily depends on how much of the relevant code and instructions it can fit in the context window.
Agreed, but I'm working on something >100k lines of code total (a new language and a runtime).
It helps when you can implement new things as if they're green-field-ish AND THEN implement and plumb them later.
In a well-designed system, you can point an agent at a module of that system and it's perfectly capable of dealing with it. Humans also have a limited context window, and divide and conquer is always how we've dealt with it. The same approach works for agents.