The antipattern here isn't that there are puzzles. The antipattern is using some external screening service using the same process for all candidates. There shouldn't even be a HR person screening before the team and hiring manager is.
(I completely get that this is unfair. If you went to MIT and have a high GPA, you are gonna make it past the gate more often. Community college, but an excellent coder? Unfortunately you will be rejected more often by HR. It's completely unfair, but companies can't reasonably interview every candidate who submits a resume.)