[bradenb]

What I've found while working in defense is that when your customer issues a statement of work with clear high level requirements then you're going to need waterfall (even if just at a high level).

[kevinmchugh]

Yeah, I think this is uncontroversial. If your problem domain generates strict, well-defined requirements, agile has less to offer.

https://www.fastcompany.com/28121/they-write-right-stuff

There might still be some useful agile practices, and you could have the less defined work (eg internal tooling?) be more agile.