at a previous gig, we put a Redis cache in front of a slow monolithic Microsoft SQL Server db that gave us breathing room to migrate the data we were intereste

at a previous gig, we put a Redis cache in front of a slow monolithic Microsoft SQL Server db that gave us breathing room to migrate the data we were interested in into a much smaller dedicated db for our purposes (the user data, used on every login and other operation in the system) in a correctly specced RDS, MySQL can be set up to store all the data both in memory and on disk (note, I'm not referring to the ephemeral disk only db engine, I'm referring to giving the RDS the correct memory settings and parameters to store all the data both in memory and on disk) once we did that, there was no difference in read speed between the Redis and just hitting the db, so we got rid of the Redis, which vastly simplified the architecture of the user service = the article title is true, caching is often understood to be a default requirement but it kind of isn't if you architect things correctly