When you want to make search fast, 80% of the job involves organizing your data so that it can be accessed with as little work as possible. This is the exact reason why Lucene is based on an inverted index. But there are some very interesting algorithms and data structures involved in that last 20% of the job. In this talk, you will gain insights into some internals of Lucene and Elasticsearch, and see how priority queues, finite state machines, bit twiddling hacks and several other algorithms and data structures help make them fast.