As a female coder in her late 40's working at , my advice to you is -- please, please pick up your algorithms book, and just study! I just helped a guy aged 60 ace the famously difficult interview at my company -- he's now working as a dev there. Basically, my role was to relentlessly tell him to study algorithms, and write code on a white board. Algorithms do NOT discriminate by age.

It seems to me that your biggest problem is that you want these guys to take all your experience into account, and they just want to know if you can code and do algorithms. There is no reason older coders can't do algorithms -- just study!

When I got the job at , in my early 40's, I took three months off and pounded CLRS, even read a bit of Knuth on hash tables, and wrote code on white boards. These interviewers don't want to discriminate -- they're going to be old, too! You just need to give them what they are looking for. And you can do it!