For every "20 min max" take home assignment, there will be people who are willing to spend 4+ hours doing it to outshine candidates who have jobs, families and lives.

If you want to make it more of a fair consideration of time, consider moving your take home to interviews, that way there isn't a time cost asymmetry. You can enforce your "20 min max" claim this way, you can judge a candidate's performance, thought process and filter out anyone who is LLMing or spending inordinate amounts of time on them.

You will also make a better impression on candidates by investing your time in them in the same way they are with you. Maybe you're hiring kids out of college without experience, but you only have to do so many take home tests before you realize that they're a waste of time, and pass on potential employers who throw them at you, or you learn to just send them your hourly rate for the test.

One other way to keep things true to the “20 min max” is to have a clear objective/scoring rubric. Nothing open ended (data science jobs LOVE handing out open ended data analyses). I need to know that it’s okay to stop and that anything I’m doing would just be overkill.

you can put a time limit on it from when they start to submit. It's really the only way to solve high volume of unqualified applicants. So much time wasted talking to people who could barely code

Live coding during an interview is one of the most oppressive things I’ve witnessed in the industry in general.

There is usually a huge disconnect between someone who knows that “this task should take 20mins” and doing it cold in a super high-pressure environment.

People sweat, panic, brain freeze, and are just plain out stressed.

I’ll only OK something like this if we give out a similar but not the same task before the interview so a person can train a bit beforehand.

I’ve heard it all justified as “we want to see how you perform under pressure” but to me that has always sounded super flimsy - like if this is representative of how work is done at this organisation, then do I want to work there in the first place? And if it isn’t, why the hell are you putting people through this ringer in the first place, just sounds inhumane.