Getting a scrolling 2D tilemap to draw was a big milestone: to get there meant I understood arrays and indirection, and those are the things you build on for mo

Getting a scrolling 2D tilemap to draw was a big milestone: to get there meant I understood arrays and indirection, and those are the things you build on for most other algorithms. The other revelation, years later, was the generality of constraint optimization as an architecture technique. Framing problems with many dependencies(time, inputs, etc) as constraint solving exercises allows them to be addressed with rank, sort and search logic. Combine those two ideas and you have most of what's needed to make systems of great complexity... ...the downside is that there isn't too much that's essential beyond that. There are specialties with innumerable depth, but they also tend to be variations on a theme and bring in concepts that are more mathematical than nuts-and-bolts computer-logic, e.g. provability.