I'm currently in the process of preparing for interviews. I'm almost 50. I'm currently talking with FANG and other well-known Silicon Valley unicorn startups so I don't feel any ageism yet. I hate it, though. But it's the reality of the industry right now. I don't pretend I'm above it, so I will do whatever I need to get a new job.
Yes, I hate them with a passion. Today I had a phone screen with a company and I was so nervous, I think I'm suffering from PTSD from how completely random the question will be, and how random the evaluator's perception of me will be based on said question. But I accept it for what it is. I'm auditioning for a role as "senior programmer", just like an actor would. That's the reality, and if I'm going to get myself a job that pays ~$400,000/yr in total comp, I will jump through whatever hoops I need to.
The OP was saying he was doing one programming question per week. Really? I'm doing 5 per night, and even more on the weekends. As I get closer to onsites, I'm going to be studying 8 hrs a day on weekends and leaving my kids to my wife.