Ever add (or inherit) the server-side part of an application that uses Redis or Memcache? The data is denormalized: When you do an update/insert/delete into the SQL side of things, you need to do a corresponding change in Redis / Memcache. All of your queries end up being something like: Try Redis/Memcache, if the data isn't present, query the database and insert into Redis/Memcache.

It (Redis/Memcache caching) adds a huge amount of complexity to your application, and the risk of defects is very, very real.

ReadySet basically gives you a magic "stick this thing between your database and application and we'll do the caching for you." It totally eliminates a time consuming and error-prone part of your application.

If you want to, they go into details here: https://blog.readyset.io/dont-use-kv-stores/