[euphetar]

I have found the following strategy to work well: pick your battles. Some employers use test tasks to keep you busy so that you can't apply elsewhere. Other employers genuinely test your skills, but even among them there are some with unrealistic expectations. You can't be doing all the test tasks, period. But you can avoid most of them without walking away.

I am assuming an active job search where you have more than one potential employers.

If the test task is simple and you have the time: do it. If the test task is interesting and you really want into this company: do it perfectly. If the test task is simple, but you don't have the time: write an email explaining how you have a full time job with lots of interviews, tell them your CV clearly demonstrates you have enough experience, ask to forgo the test task. If the test task is hard and you don't have the time: explain how you would do the task, ask to forgo the task as above, walk away if they don't agree.

You would be surprised how often people will skip steps of the interview process if you ask nicely. This way I skipped tedious home assignments, psych tests and leetcode home assignment (not even hard, just told the company I don't want to rehearse dynamic programming with so many interviews lined up).

In my recent job search I had two good offers and incidentally both were the ones where I did the test tasks 150% because they were interesting. So do them if they are worth it.