When Luminar started building its workflow a year ago, it didn't even have an auto-merge capability, and the team began with manual updates of pull requests.
The engineering team works in a so-called monorepo, and 70 developers contribute to it daily. They leveraged the branch protection system from GitHub, using simples rules such as needing at least two code approvers, forcing the pull request to be up to date with the main branch, etc.
This workflow was very limiting. The build time was between 1 and 1.5 hours. Developers were spending a significant amount of time trying to update their pull requests as soon as possible to get merged. They needed to be part of the first ones doing an update to have a chance to get their pull request merged.
The CI team started to look for solutions. Writing an automation tool would be possible, but it wasn't their core skill set. Finally, they found Mergify and a competitor by looking up ''GitHub Merge Queue''.
Mergify was the clear winner with its efficiency.