This abstract provides a comprehensive comparison between RocksDB, LMDB, and MongoDB, three popular database systems, highlighting their differences in terms of architecture, performance, scalability, and use cases. RocksDB, an embedded key-value store developed by Facebook, and LMDB (Lightning Memory-Mapped Database), a memory-mapped key-value store, are both optimized for high-performance and low-latency workloads. These databases excel in scenarios where efficiency and speed are critical factors, such as caching, session stores, and other applications that require fast data access. RocksDB is known for its persistent storage on disk and seamless integration with various programming languages, while LMDB leverages memory-mapped files for exceptional performance but lacks distributed capabilities. On the other hand, MongoDB, a document-oriented NoSQL database, offers a flexible schema and a rich set of features for handling complex data structures. MongoDB is highly scalable and