For those who missed it, a HN user is working full-time on dynamic optimizations in Ruby (just finished his PhD thesis on it) - https://news.ycombinator.com/item?id=10791428 - It's showing significant (10x) speed-ups using real interesting methodologies. He's working on it full-time as the project lead at Oracle now. That thesis is worth a week-end read, it's something I would dedicate 4-6 lectures to if I was a professor.