Books I actually use.

The syscall reference I reach for first. It also shows how much the kernel hides from you.

Useful for turning a vague feeling of slowness into a number. The memory and file-system chapters are the ones I revisit.

A clear map of replication, partitioning, and consistency. The bibliography is the useful part.

The clearest explanation of Pratt parsing I have read.

Short, and it gets you to a working tree-walking interpreter without much ceremony.

The database course I wish I had taken earlier. Query execution and buffer management are the parts I used in abdb.

Still the fastest way to remember what a socket call actually does.