I only made it through the first three steps:

1. A 20-30 minute personality test
2. A 30-minute phone interview with an engineer
3. A 3.5-4 hour long proctored assessment

None of these steps were too difficult, but this was a major time sink. The rejection letter was very sparse, just stating that they are not proceeding with my application. I asked if I could have any feedback, and they replied that they do not provide feedback and that I can apply again in one year.

I guess I feel that after spending 5 hours of my life just to do their assessments, the least they could do is tell me what I could improve on. It seems exploitative to expect so much when they offer nothing in return.

A 4-hour assessment covering logic, programming, and basic math.