Disclosure: I work for Amazon, but not directly on search related technology. Some information about Amazon's investments in upstream Apache Lucene can be foun

Disclosure: I work for Amazon, but not directly on search related technology. Some information about Amazon's investments in upstream Apache Lucene can be found here: https://aws.amazon.com/blogs/opensource/amazon-giving-back-apache-lucene/ https://aws.amazon.com/blogs/opensource/amazon-giving-back-a... Covered in the 2019 blog post are: * Concurrent updates and deletes * Indexing custom term frequencies * Lazy loading of Finite State Transducers