As part of the cleanup operation regarding our backend codebase, we were migrating to a new format of fetching the backend from our repository hosting service GitHub. Unfortunately, the new backend code depended on a newer version of the database program and as a result we could not finish the migration in a timely manner.
Nothing, apart from the downtime. The migration was slow to complete since we had to perform it manually, but it was successful and no data was lost. We keep backups to ensure that we can roll back immediately if we detect any problems or instability in the system.
In the future we plan on making automated scripts to ensure that the migration process goes smoothly.