# Perplexity — Photon: Building a Retrieval and Ranking Engine From Scratch

- Company: Perplexity (perplexity.ai)
- Announced: 2026-09-24
- Category: infrastructure-release
- Coverage: not counted
- Announcement: yes
- Group: announcements
- Source: https://www.perplexity.ai/hub/blog/photon
- Record: https://forck.live/items/13742-photon-building-a-retrieval-and-ranking-engine-from-scratch
- Subject: Perplexity

Perplexity built Photon, an in-house retrieval and ranking engine designed to replace an open-source platform that faced scaling costs, tail latency, and recovery time constraints. Photon powers Perplexity's search pipeline and a new fast preset for its Search API, achieving single-search-call latency of 160 ms at p50 and 230 ms at p95, and reducing estimated model-plus-search cost per task by 68% across six public benchmarks while maintaining comparable task quality.

## Evidence

Verbatim from https://www.perplexity.ai/hub/blog/photon:

> Photon now powers our search pipeline and is also the foundation of a new fast preset for our Search API, with single-search-call latency of 160 ms at p50 and 230 ms at p95. Across six public benchmarks, the fast preset reduced estimated model-plus-search cost per task by 68% while maintaining aggregate task quality comparable to the default preset.

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