Perplexity Introduces Photon: A Rust-Based Retrieval Engine That Cuts p99 Latency From 800 ms to 65 ms

Perplexity has launched Photon, an in-house retrieval and ranking engine written in Rust that replaces its previous open-source system. By optimizing search infrastructure, the company reduced its p99 latency from 800 milliseconds to 65 milliseconds for all production traffic. This change also supports a new Fast Search mode now available to users.