as a 20+ year developer, this is excellent. One of the bigger leaps for me (which the author mentions) was going from toy CS assignment projects where I wrote all the code and knew it inside and out to huge multi year projects with hundreds of developers. It was a giant spaghetti code of math heavy C/C++. I was always surprised it worked at all. You don't even know where to start to add some feature (don't panic!). Some highlights where comments above a particularly tricky function was something like: "do not change this, you think you understand it, but, you don't. move along" and something like: "In Graecia antiqua, pueri tui similes in extremis rupibus remanserant mori." (latin for "In ancient Greece, children like you were left on the edge of cliffs to die.")