[throwawaybcknd]

> there's the philosophy that good engineers can apply learnings from one domain to another, and therefore a senior is a fungible resource.

I see that a lot. I mean, JavaScript isn't hard to pick up, but the front-end is not an operating environment that resembles anything else I have ever seen.

> Personally, I'm in the former camp- true full-stack is a unicorn,

I think that's the case, too. iOS or desktop applications, I've played with those, I've done games on tiny hardware, those feel like I'm using the same part of the brain the rest of the computer science lives in, but I don't think it's possible to have a thorough understanding of the browser environment and be equally good with anything else.