The new popular pages bot has a database, with a single table that keeps track of the projects and the date they were last updated on. However the database does not keep up with the config page, so any new project or deleted project won't be reflected on the db.

Instead of inventing a system to keep them in sync, I'm thinking of dropping the database altogether and instead using the API to get the last revision timestamp for the page. This seems like a quite simple solution with a pretty low chance of false positives (such as when someone other than the bot wrote to the page). We can also investigate if the API can tell us the last time the bot updated that page but I'm not sure if it can.