MongoDB and Stratio built an Operational Data Lake for one of Spain's largest insurance companies, Mutua Madrileña, to improve customer experience and optimize marketing ROI. The data lake aggregates data from multiple sources using Apache Kafka and Apache Flume, is stored on Apache Hadoop, and serves analytics models to operational applications via MongoDB and Postgres. This setup enables personalized user experiences, risk classification, and improved marketing campaign performance through the use of machine learning models built with Apache Spark.