Perplexity replaces DynamoDB with in-house CobbleDB, cutting read latency 5x

Perplexity moved its search serving tier off Amazon DynamoDB to CobbleDB, an in-house distributed key-value store written in Rust. Median batch-read latency dropped from 31.4 ms to 5.6 ms, p99 fell from 123 ms to 24.2 ms, and storage costs dropped at least 20%. The company plans to open-source the code.

• Median batch-read latency fell from 31.4 ms to 5.6 ms; p99 from 123 ms to 24.2 ms
• Cloud storage expenses cut by at least 20%
• CobbleDB is 40,000 lines of Rust built by two engineers in two months
• Storage split into Pillar, Lorry and CobbleDB; code to be open-sourced