Fireworks: open models plus fine-tuning match closed ones — Cursor gets 13x faster inference

AI Engineer · youtube · 2026-10-12

A talk by Jetashree Ravi of Fireworks AI at AI Engineer World's Fair on moving from renting closed intelligence to a train-to-deploy loop.

Three truths: open models like GLM 5.2 are production-ready; customization closes the quality gap with closed models; the AI stack is shifting to a continuous train-and-serve loop.

Scale and results: 30 trillion tokens served, 10,000+ companies; Cursor's Composer 2 trained and hosted on Fireworks with 13x faster inference; 40x latency improvement for Vercel; 12% quality gain for Genspark via RFT.

Tech: FireAttention engine with custom CUDA kernels, speculative decoding with custom draft models, three training paths (training agent, managed training, training API for SFT/RFT/DPO), one-click deploys, monitoring, hot-loading weights with zero downtime, and numerics matching between training and serving.

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