[dkoston]

I think I see where you are coming from. Being as we use different tools, we wouldn’t allow a pull to be merged if it wasn’t up-to-date with master which is similar but a different approach. You’ll have to check at merge time because getting up-to-date could take a while and master could have changed. Jenkins does this and it can be done in other CI/CD systems with a bit of custom code.

I’d imagine at 1,000 developers and with a monolithic codebase, you’re looking to minimize test runs both from a time and cost of runners perspective.

You may also want to look into Zuul or Bazel if cost of test suite runs is a factor in coming to this solution.

[wvanbergen]

> Being as we use different tools, we wouldn’t allow a pull to be merged if it wasn’t up-to-date with master which is similar but a different approach

That wouldn't work for us due to the amount of changes we need to ship. If you rebase your branch and wait for CI to come back green, chances are another PR will have merged in the mean time, which means your rebased branch is no longer up to date with master. You end up stuck in a rebase cycle.

For this reason, we have no choice but to batch PRs, which is what the merge queue tool does. Faster CI will reduce this problem and we're working on that as well, but won't fully solve this.

[dkoston]

That’s understandable. I’d imagine at some point you’ll need to decouple the monolith a bit in order to work effectively as you scale. Best of luck with the challenge.