eHarmony, a leading relationship service provider, migrated its database from relational technology to MongoDB, resulting in significant improvements to customer experience. The company now processes matches 95% faster and has increased subscriptions by 50%. eHarmony's data science team uses sophisticated compatibility models, machine learning, and predictive analytics to match prospective partners. After exploring other solutions such as Apache Solr and Cassandra, they selected MongoDB due to its ability to support complex queries, flexible data model, and scalability on commodity hardware. The migration has also enabled the company to integrate with Hadoop, Apache Spark, and R for predictive analytics, leading to a compelling ROI. eHarmony plans to expand their services to 20 new countries and explore applications in the jobs market, leveraging MongoDB's geospatial capabilities and pluggable storage engines.