Meaning
A high-speed data storage layer that stores a subset of data temporarily so future requests are served faster.
Three examples from work
Performance tuning
DevAdding a Redis cache dropped database read queries by eighty percent.
LeadWhat is our cache expiration and TTL policy?
Debugging stale data
QAThe user avatar does not update immediately after uploading.
Frontend DevThat is an aggressive CDN cache; I'll append a cache-busting timestamp query.
Architecture review
ArchitectCache invalidation is one of the hardest problems in distributed systems.
DevWe use pub/sub events to flush stale cache entries instantly across nodes.
Pronounce like 'cash'. Can be a noun ('in the cache') or verb ('cache the response'). Always establish clear TTLs and invalidation triggers.