Yesterday I read that Google actually decreases their expectations in the white boarding exercises for experienced hires because they realize the leetcoding techniques will not be as fresh in an experienced dev's mind. The expectations are higher in regards to system design and resume questions. That seems to be fair imo.

Later in the material it said that they reject over 80% of people who make it onsite. The bar at FAANGs is just relatively high regardless what kind of role you are trying to get. My mentality is preparing for high bar whiteboard interviews best case lands a job at a FAANG and worst case makes it incredibly easier to land a job elsewhere at a company that doesn't rely on whiteboarding or has a lower bar in general. That's to say investing in whiteboard practice has little downside and has an acceptable time/reward ratio given the results if you are even just ok at it. In terms of ageism whiteboarding is not required to filter older devs out. Resumes viewing can do that. Why would they waste 6+ hours of their expensive Sr. devs time to put someone through a pointless exercise? Serious candidates will commit the same 1-3 months of study whether they are 23 or 43.