This isn’t directly related to memory techniques, but programming has some similarity with mnemonic systems in that symbols encode meaning. There are some esoteric programming languages that contain interesting ideas that I thought people might be interested in.
Check out Piet, Whitespace, and Befunge here:
Whitespace is a polyglot language, meaning that one file of code could be executed in two different language interpreters.
There are other ideas here, like Velato which converts music into logic: