What is Caching?


#1

What is caching ? and its relation to deactivation of accounts ?! (Simplified answer)


#2

Caching is when a value for something is persisted for an amount of time or until expired – instead of verifying the current value for something every time you request a value, a “cached” value is presented instead. On Twitter, this helps make serving data at scale possible as we don’t have to look up the value for something from disk every time the data is requested.

All data on Twitter is cached to a certain degree. When a user changes state – like from an active account to a deactivated account – it can take time for the cached representations reflecting that user to expire and new values to take their place.


#3

The deactivated account data still saved … and searchable for API ?!


#4