[arek2]

I have not seen the Stockfish source, but my impression is that computer chess was going round in circles in the last 10 years, and it's still good old alpha-beta search with more refined heuristics.

The biggest value in studying computer chess for a programmer is IMO in seeing all the different performance optimization tricks.

[halfcat]

Performance optimization, while it is not neglected, is not what separates chess engines. You don't win an exponential race with linear advantages.