I have a few different sites hosted on Firebase. It has become my go-to solution for hosting static sites.
A common problem that I ran into is that Firebase kept each release of a site for history and rolling back. That isn't necessarily a bad thing except that those old releases count against your storage quota. Which means you could run out of storage on the free tier or rack up some unexpected charges on the paid plan.
You had the option to delete old releases, but it was a manual process to click each release, choose delete, and then confirm. It was not a great experience, especially if you've automated the deployment of your sites to Firebase.
Searching for an automated solution would eventually lead you to this comment where you could vote for a proposed solution or to a GitHub repository for a script with web requests to delete the old versions.
In March 2019, Firebase added release storage settings for hosted sites. For each site, you can specify how many old versions to keep, and Firebase will do the deleting for you.
If you're like me, and initially missed this feature release, head over to the Firebase console to set the release storage settings for your sites!