TL;DR - Caching done badly has bad implications. Try your hardest not to cache data; but if you really do have to, make sure you do it right.
There are only two hard things in Computer Science: cache invalidation and naming things.
– Phil Karlton
Caching?
To make sure we’re on the same page, when I say caching, I am talking about the practice of speeding up your own application by masking slow dependencies by remembering previous responses and using them instead of making another slow call to the dependency.
As mentioned briefly by Phil Karlton in his well known sound byte, caching is a tricky problem. This is compounded by a number of common mistakes which I have seen over the years which have resulted in unnecessary confusion delay.
Common Mistakes
Here are some of the mistakes I have seen and what we should to differently.