[_xiaz]

Most of these wouldn't qualify as "puzzles", would they?

I find it nice to learn new languages via data structure puzzles, because to me the data structures of a language feel like the grammar and once I have that down everything else falls into place

[joshlemer]

I disagree. Yes, you have to learn how to work with the basic data structures of a language, but 90% of programming, for most people, is not that. It's IO, error handling, db querying, logging, input parsing, parameterization, business logic, preserving backwards compatibility, persistence, state management, testing, mocking, benchmarking, build design (for lack of better term -- futzing around with Make/Gradle/Npm, Dockerfiles). All of that doesn't just fall out of learning DS/Alg's, it takes time to become familiar and fluent in how all these are done in your ecosystem.

When employers or team mates ask you if you "know" or "are competent in" Java they don't care if you know how to work with lists, arrays, loops, hashmaps and sets. Well, I mean, that's table stakes. They're asking if you're familiar with the idiosyncrasies of the language with respect to those above concerns.

[_xiaz]

Imo DS/Algs to an extent are a good prerequisite. Once you know them in one language that knowledge is portable enough to get you up-to-speed in $lang. Then, and no earlier will I start worrying about doing real things in my programs and the "idiosyncracies"

[xigoi]

I think you overestimate the proportion of programmers who primarily work on corporate stuff.