Lots of the ones already mentioned here are great. One I don't see mentioned here is Eric Lippert's blog. He is just now concluding a 35-part series on Conway's

Lots of the ones already mentioned here are great. One I don't see mentioned here is Eric Lippert's blog. He is just now concluding a 35-part series on Conway's Game of Life and in particular the Hashlife algorithm, which includes one of the most mind-blowing programming concepts I have had in years. https://ericlippert.com https://ericlippert.com