[the_mitsuhiko]

I don't know what your hiring experience with this is, but there is an entire market around "coding interviews" where people will learn how to pass these. I found algorithmic interviews completely useless to assess junior engineers because of how many just learn just to pass interviews, but then have very little experience with real problems.

[heavyset_go]

If you want an example of this, check out r/cscareerquestions. The standard advice is not to practice any practical coding with projects, but to "grind leetcode" to get past interview filters.

[watwut]

If you want experience with real problems, they juniors should not be your thing. Juniors are supposed to be people with little experience that are able to work if given tasks by seniors.