When you're building a serverless web app, it can be pretty easy to forget about the database. You build a backend, send some data to a frontend, write some tests, and it'll scale to infinity with no effort, right? Not quite. Especially not with a tiny Postgres server. As the number of users of your frontend increases, your app will open more and more database connections until the database is unable to accept any more. That's just the frontend - it gets worse on the backend.