Productboard doubled its engineering team in just 1 year, from 70 to 150 persons. It was a huge problem for their front-end repository: it consists of a single repository for everything.
To face this challenge, they deployed a merge queue, but they scaled faster than the merge queue could handle the load. They were in a situation where things weren’t working very well, obligating them to use nonoptimal tools to merge the first pull request in the queue, update the second one, run all the checks again, and merge the result.
The time needed for the checks in between was around 25 minutes for each pull request. In 24 hours, they had a hard limit number of commits they could merge.
Moreover, most engineers are based in the Czech Republic; in peak hours, engineers could spend a couple of hours before getting their pull request merged. That was the situation they were trying to solve; bottleneck.
The situation escalated quickly. People were waiting 4 to 5 hours to merge their changes, while their goal was to merge around 150 pull requests a day.
That was the breaking point and when they decided to switch to Mergify.