A few years ago we started using HackerRank and created a test with 4 or 5 coding questions for candidates to do on their own. They could pick the programming language from about 10 options and the questions had varying degrees of complexity, with one being particularly difficult.

I sent it to almost all engineers on the team before we started using it and none could hit a 100% on it.

We still went ahead and started using it in our process. Non surprisingly, most folks would fail to get a perfect score but we still use it to see what they tried and also one of the following interviews was a review of the whole test with the applicant as we discussed their thought process and what other odeas they may have come with since they took the test.

Our intention with the test was mostly basic problem solving skills and was the first step in the process so it also worked as a filter.