CACHING IS AN ABSTRACTION, NOT AN OPTIMIZATION

Summary from the TLDR newsletter

Caching is best understood as a tool for making software simpler rather than as a tool to improve performance. It resembles an abstraction rather than an optimization. Understanding this makes it possible to come up with designs that work and satisfy the functional requirements of systems from the perspective of 'having adequate, fast access to the data it needs'. The problem should be figuring out how to get data into fast storage as often as possible instead of gaming a system that is holding data access storage.