No More Waiting in the Dark: Introducing Build Queues

By: Michael R. Bagnall

Last Updated: April 2, 2026

One of the most common questions we heard from teams using Probo.CI was simple: “Why isn’t my build running yet?” Sometimes a build would sit without any visible explanation, and there was no good way to tell whether something had gone wrong or whether it was just waiting its turn.

That changes today. Probo.CI now has a proper build queue, so a waiting build is never a mystery - it is simply in line for the next available slot.

What Is the Build Queue?

Every Probo.CI plan includes a limit on how many builds can run at the same time. When your team has more active builds than that limit allows, the newer builds wait in line. That is the queue.

How It Works

The queue is simple and fair:

• Builds run in the order they arrive. When a build slot opens up, the build that has been waiting the longest goes next. No build jumps the line.
• Queued builds start automatically. You do not need to do anything. The moment a running build finishes and a slot frees up, the next build in line starts on its own.
• Queued builds do not expire. A build will stay in the queue until it runs or until you cancel it - it will not time out or disappear on you.

What Happens When a Pull Request Is Updated

If you push new commits to a pull request while its build is still running or waiting in queue, Probo.CI starts a second build for the new code. The original build is not cancelled or replaced - both builds will run to completion.

Once you no longer need the outdated build, you can delete it yourself from the build page in the portal using the trash can icon. If you leave it in place, it will eventually be removed by the Reaper, our automatic cleanup process, once both builds have completed and your organization approaches its storage limit.

You can also delete a queued build manually at any time - say, you have decided a PR is not ready yet - directly from the portal. If you close or merge a pull request while it is building, that build is immediately reaped.

Queue Visibility

The portal shows how many builds are currently waiting in your organization’s queue. This gives your team a quick sense of how busy things are - whether a build should start soon or whether there are several ahead of it.

Note that visibility is limited to the queue count. The portal does not currently show which specific builds are queued or the order they will run in. Because the queue is strictly first-in, first-out, you can rely on builds starting in the order they were submitted.

Getting More Concurrent Builds

If your team regularly has builds waiting in queue, that is a sign you might benefit from a plan with a higher concurrent build limit. More concurrent builds mean less waiting and faster feedback for your team.

Visit our pricing page to compare plans, or get in touch with us if you want to talk through what makes sense for your team.

Questions?

If you have any questions about build queues or how to manage your builds, please reach out to us at hello@probo.ci. We are happy to help.