This is the omegaUp backend. It's composed of a few components:

• grader: Manages the run / submission queue. Does not run anything.
• runner: Communicates with grader to request new submissions to grade. This compiles and runs the code using the omegajail sandbox against all the inputs, compares the outputs to the expected ones (running a validator against them if needed), and assigns scores to each run.
• broadcaster: Broadcasts notifications to users in a contest / course. Things like new runs being graded, scoreboards changing, clarifications, etc.