I replaced Auth0 with an open source library in 30 minutes. Here is what broke.

My Auth0 bill last month was $427. For 12,000 monthly active users on a side project that makes roughly $0 in revenue. I spent a Saturday moving off it. This is what happened. Auth0's pricing jumps at the 1,000 MAU line. My project crossed it in March. The next tier is $240/month. Then I turned on M