CockroachDB initially built its infrastructure on RocksDB, a key-value storage engine based on log-structured merge trees (LSM), due to its rich feature set essential for a distributed SQL database, despite transitioning to their own Pebble engine later. RocksDB's capabilities, such as prefix bloom filters, fast scans, snapshots, and custom key comparators, are crucial for addressing the performance and complexity of distributed systems, allowing CockroachDB to translate SQL operations into key-value operations efficiently across multiple nodes. While RocksDB's C++ foundation poses challenges in integrating with CockroachDB’s Go-based system, the benefits of its comprehensive features, like SSTable ingestion, range deletion tombstones, and encryption support, outweigh these drawbacks. Cockroach Labs continues to leverage RocksDB for its high concurrency and performance needs while acknowledging the potential advantages of a Go-native storage engine to streamline operations further.