Cosmos DB is a globally distributed, multi-model NoSQL database service designed to support mission-critical applications that require low latency and high throughput. It supports various data models, including document, key-value, graph, and column family, and it is highly scalable with automatic replication across multiple regions. Cosmos DB provides five different consistency levels and offers multiple APIs for accessing data, including SQL, MongoDB, Cassandra, Gremlin, and Table APIs.
A large multinational e-commerce company uses Azure Cosmos DB for its real-time order processing and recommendation engine, while storing product catalogs and inventory data in Google Cloud Spanner for global replication. The company also uses Amazon RDS for some operational workloads for its better integration with AWS-based legacy applications. By leveraging multiple services, the company optimizes latency and availability for users across different regions, ensuring seamless service.