Nolan Lawson explores why developers often build custom solutions instead of using native APIs, largely looking at JavaScript, but it's something that shows up in most languages and environments, for good reason.
Kenta Cho built a Z80 REPL: type an instruction, execute it immediately, and watch the machine state change. It's eight years old, still delightful, and a neat example of what happens when good tooling makes experimentation cheap.
Christian Rackerseder makes the case that developer experience is a performance feature.
The stronger version of his claim is that developer experience is an epistemic feature.
Good performance is just one of the things that falls out when your team can finally see what it has been shipping.