[lmm]

Sounds like you've had a very interesting career; I'm curious where you've worked. My impression is that most programming jobs are about CRUD-like problems, adapting well-known technology to solve business problems. CS seems like it could only help if there's a well-known algorithm (that would be taught in CS), but no existing implementation available - but in these days of open-source libraries that practically never happens.

FWIW I switched out of CS into Mathematics after one year. I've never implemented A*, I've used raytracers but not implemented my own, used a bloom filter but not implemented it, used an lru cache but not implemented one, used adaptive windowed linear regression but never implemented it myself. When optimizing database queries I've never needed more than EXPLAIN SELECT; when optimizing performance I've never needed more than a language-level profiler. I did actually implement an RFC from scratch (SMTP), but that was easy enough to do by, well, reading it and implementing it.