One programming job may require a completely different skillset than another. Going over the Hackerrank algorithms, how many times do you do things like fancy

One programming job may require a completely different skillset than another. Going over the Hackerrank algorithms, how many times do you do things like fancy bit manipulation or game theory algorithms for building a simple CRUD web app? There are certainly programming jobs where bit manipulation is common (systems level / embedded code is one I can think of) but from my experience it's pretty rare to XOR bits in Javascript land. Same with things like data structures. Again: in the world of C / C++, certainly you'd use trees / linked lists / etc. I do think is good to know about these concepts regardless so that this type of thing is more than just vague black box magic, but in Javascript CRUD web app land all of that stuff is mostly "behind the curtain", so it isn't the most necessary skill to have. Hackerrank in fact seems really poorly suited to web development positions. No tests on CSS, HTML, design patterns (yer model-view-* patterns, dependency injection, responsive web design, etc etc.), data transmission structures (eg JSON and XML), browser structure (eg the DOM), dynamic communication (eg Ajax/XHR, Websockets), etc. Heck, Hackerrank may show that you can write some SQL, but ironically for something with "hacker" in it's name, it can't show that you know about how to mitigate the common "web hack" tricks (eg SQL injection, XSS vulnerabilities, URL fuzzing), something I would think would actually be way more relevant for any public CRUD web app.