Savory is a web app to organize and manage your long reading list, bookmarks and references. Since launch in May 2020, Savory has used MongoDB Realm for its backend, which was nothing more than a lightweight wrapper over the underlying MongoDB Atlas cluster, with some custom authorization rules sprinkled on top.
The original backend design, or the lack thereof, was good enough when we were just getting started. But as the number of bookmarks grew, performance issues started showing up. Page load time shot up to double-digit seconds for me (6000+ bookmarks). This is partly because I am in India and the database is hosted on the other side of the world in Oregon, US. But one of the major self-inflicted problems with the design was that we were loading and returning all the bookmarks for a user from the database at page load. Yes, all 6000 of them in my case. Every time.