- Embarrassingly low-level (chip developers): OS, C/VHDL/Verilog, MA, DS, GPH, EE, Apathy, SE
- The in-betweeners (kernel, device, storage developers): OS, C, MA, DS, GPH, Apathy, Crypto, SE
- Low-Low-level systems: OS, C, DS, GPH, Apathy, Crypto, SE, FTDS, MSG, NW.
- Low-High-level systems: C/Rust, DS, GPH, Apathy, HDS, Crypto, SE, FTDS, MSG, NW, TL.
- Unicorn rock-star systems hacker (perhaps only a handful
of these creatures exists :-): Multiple OS, C/Rust/JVM/Erlang/Haskell, Multiple MA, DS, GPH, EE, Crypto, FTDS, MSG, NW, HDS, SSE, TL.
GPH = Good Programming Hygiene
EE = Electronics and Electrical Engineering
OS = Operating System
MA = Modern Assembly
DS = Data Structure
FTDS = Fault-Tolerant Distributed System
MSG = Messaging System
NW = Networking
TL = Toolings (the darlings of UNIX)
HDS = High-Density Systems
SE = Security Engineering