[jerska]

Custom-made C++ engine - baked into an nginx plugin - no elasticsearch nor lucene in the stack, except to gather analytics on the side. It has been made to solve user-facing search only, where elasticsearch couldn't meet the same speed because it's trying to solve a lot of other things.

[dzello]

More information about the tech stack here - https://stackshare.io/algolia/how-algolia-reduces-latency-fo...

[aphextron]

Cool, thanks. Good to know they've got some special sauce.