I had an interesting conversation with some junior and mid-level engineers recently. They were pretty discouraged about whiteboading coding tests. Apparently, they've gotten significantly harder over the last two years. Everyone's inverting binary trees these days. I got my hands on a few questions they've given someone with 1 YoE and 3 YoE. They were extremely hard, especially for someone at that experience level. I think these companies are not actually testing problem solving ability anymore....