Last weekend I watched this video of Andreas Kling prototyping a JIT compiler for his Ladybird browser:
One: if you’re interested in how bytecode VMs and JIT compilers work, it’s all in there, explained step by step. A goldmine, really. If I had had a video like that 6-7 years ago I might not have written my books.
Two: how Andreas builds this JIT compiler is endlessly fascinating. It’s clearly visible that he’s spent thousands and thousands of hours of his life programming. It shows up in the large (hey, he knocks out a JIT compiler in 1.5hrs) and in the small – little tricks and moves and shortcuts. The latter is what’s so fascinating, because usually you don’t catch these small things on video, forget that you did them or don’t think they’re even worth mentioning.
I haven't watched the video yet, but I've seen other references to it and I'm definitely going to check it out. I have already previously been impressed by Andreas as a person and as a programmer.