thanks for this.

> the term originates from Michael Feathers Working Effectively with Legacy Code

I haven’t read the book but, taking the title and Amazon reviews at face value, I feel like this embodies Codex’s coding style as a whole. It treats all code like legacy code.

It's not in the top 10, but it's of the more well-known and widely recommended book in the software industry. I'd put it in the same bucket as "Clean Code" and maybe even "Domain Driven Design"; they're kinda from the same "thought school" in the software industry. So it's definitely over-represented in training data (I'd guess primarily in the form of articles and blog posts and educational material reiterating or rephrasing ideas from the book).

FWIW, I found the concept of "seams" from that book useful back when working on some legacy C++ monolithic code few years back, as TDD is a little more tricky than usual due to peculiarities of the language (and in particular its build model), and there it actually makes sense to know of different kind of "seams" and what they should vs. shouldn't be used for.

It's been a long time since I read it, but it was one of the better books I've read. It changed my approach to how to think about old code-bases.