Can you comment on how the IDE performs on large codebases? Does the spec based approach help with it? Any examples you can give from experience at Amazon?

It works great in really large codebases!

I've published a sample project that is medium sized, about 20k lines encompassing a game client, game server, and background service: https://github.com/kirodotdev/spirit-of-kiro This has been all developed by Kiro. The way Kiro is able to work in these larger projects is thanks to steering files like these:

- Structure, helps Kiro navigate the large project: https://github.com/kirodotdev/spirit-of-kiro/blob/main/.kiro...

- Tech, helps Kiro stay consistent with the tech it uses in a large project: https://github.com/kirodotdev/spirit-of-kiro/blob/main/.kiro...

And yes, the specs do help a lot. They help Kiro spend more time gathering context before getting to work, which helps the new features integrate into the existing codebase better, with less duplication, and more accuracy.