Our Systems team is in charge of a lot of stuff:
- Math Library
- STD Replacement Library
- Core Game Framework
- Core Application Framework
- Input
- Event messaging
- Component-Entity systems
- Script binding
- (and more)
There's a lot of Windows and Linux domain knowledge here as well as a lot of knowledge of Physics, core game logic and low level memory management.
Systems teams will usually be involved at least in some part in each supported OS since most of their projects sit on each OS at a pretty low level.
Some things that might fall under a "Systems" team that we break up into separate teams (but our Systems team still interacts with pretty heavily):
- Physics
- Linux (dedicated server)
- Direct support for other OSes (iOS/Mac/Consoles/etc)
- Build Systems
- Audio
Operating Systems Three Easy Pieces
Low Level Programming Assembly Execution Architecture
The Linux Programming Interface
Making Games for the Atari 2600