Epicery tried to keep their pull request up to date with their base branch by constantly rebasing them. This would take a lot of time, even when automated with a script, and would continuously triggers their CI, continuously increasing cost.
The team also had no way to be notified when a pull request was conflicting. That meant the author would be misled thinking its pull request was mergeable, while it was not and would be ignored by reviewers.
Leveraging Mergify, Epicery engineers were able to limit their pull request rebase usage to a bare minimum, saving a lot of CI time. They also were able to build a custom workflow that notifies an author when its pull request needs to be manually updated because of conflicts.
Finally, Epicery engineering team was able to streamline their dependency management updates. They wrote rules that defines precisely how and when to merge them, automating part of their security process.