Companies constantly talk about how expensive it is to hire people because your most valuable employees have to spend time prepping for interviews, reviewing homework, discussing results etc.

In the era of full remote work I don't understand why you don't just have a small greenfield project that you can quickly onboard prospective employees with. Have a brief personality / resume griller screening, then hire them for a week and toss them at a few bugs or issues for this project with a semi-public slack. Then see what they output and decide at the end.

That would likely be less expensive then all the other nine layers of interviewing hell they maintain and get better results.