Understanding Database Sharding
This article doesn’t focus on one database technology in particular but instead focuses on the theory of database sharding and different sharding architectures. I also liked that it admits that sharding is tricky and provides a list of things to investigate before going down the path of sharding.
You are thinking about serverless costs all wrong
One thing you do hear about building serverless applications is the cost, and that is a completely valid concern. If you have millions of function invocations per day, then things are going to get expensive very fast. The thing is, that is not a good use case for serverless. This article dives a bit deeper into the costs of serverless and when they may make sense.