Perplexity decided it was paying too much for DynamoDB and wasn’t getting the control it wanted over read performance. So it built its own database: CobbleDB. Built by two engineers in two months with help from hundreds of persistent coding agents throughout development, CobbleDB is a roughly 40,000-line Rust key-value store that now handles part of Perplexity’s production search traffic. The company measured median batch-read latency at 5.6 milliseconds after the move, compared with 31.4 ms on DynamoDB before the cutover, while p99 went from 123 ms to 24.2 ms. It’s expected to cost at least...

Source: The New Stack