Perplexity's AI agents helped build a database. They weren't allowed to run it.

Perplexity replaced DynamoDB in its search stack with its own database CobbleDB: about 40,000 lines of Rust written by two engineers in two months with the help of hundreds of coding agents. Median batch read latency dropped from 31.4 to 5.6 ms, p99 from 123 to 24.2 ms, expected savings at least 20%.

• Median batch read: 5.6 ms vs 31.4 ms for DynamoDB
• p99 dropped from 123 ms to 24.2 ms
• In load test CobbleDB handled 500,000 requests per second
• Expected savings at least 20%, database planned to be open-sourced