To provide the data that users consume through the Yelp mobile app and website, Yelp leverages materialized views wherein data is collected from various sources, transformed, and stored in Cassandra for fast retrieval. Recently, Yelp redesigned the indexing process for this system to improve its scalability, reliability, and ease of use. Their new system, ElasticIndexer2 leverages MySQLStreamer for change data capture (from MySQL to Kafka topics) and several Flink-based services for stream processing.