Model-based development, formal verification, and trusting software used in cars: https://www.theatlantic.com/technology/archive/2017/09/saving-the-world-from-code/540393/
Related Posts
Learning software development through playing and contributing to a MUD: https://tashian.com/articles/how-i-learned-to-program/
"Example Driven Development" using Glamorous and Pharo Smalltalk: https://medium.com/feenk/an-example-of-example-driven-development-4dea0d995920
Tests returning values and composing is a really interesting model. It establishes structure and shows which test failure is the most 'fundamental'.
What are the most popular languages that have used an AST walker for their implementation?
I know Ruby used to do this, but there must be others.
(I'm interested in the lowest PL speed that users will tolerate if you have awesome features.)