Migrating Classic Slack Ruby Bots to Granular Permissions

Slack recently introduced granular permissions and is now requiring all new apps to use those. The old apps are called classic apps, and new apps are called … apps. Slack also provided a migration guide.As of December 4th, 2020 Slack no longer accept resubmissions from apps that are not using granular permissions. On November 18, 2021 Slack will start delisting apps that have not migrated to use granular permissions. So you better get going with a migration ASAP.I found the migration quite challenging for my many real-time bots with existing customers. New bots cannot use real-time, and there’s no way to automatically migrate existing installations - users must reinstall a newer version of the bot. I chose to avoid a data migration and picked a path of upgrading the bot to granular permissions, then operating both the old and the new version on top of the same database.