What does "backlog" in traviscistatus.com mean?

For a multi-job build, only a few jobs are running at a time, the others are waiting in backlog. However, the “backlog” in https://traviscistatus.com consistently says “0 jobs”.

So, what does that “backlog” actually stand for?

“Backlog” means the number of jobs that are waiting for an available VM to be able to start. When the backlog says “0 jobs”, it means no job is currently waiting to start hence your builds should start quickly. Does this help?