World's Fair 2025
Dream Machine: Scaling to 1m users in 4 days — Keegan McCallum, Luma AI
Overview
This talk details Luma AI's experience scaling their Dream Machine video generation model to one million users in four days. It covers the immense infrastructure challenges faced during the launch, including the need to rapidly scale GPU resources from an initial 500 H100s to 5,000. The presentation also discusses the evolution of their serving stack from a brittle, coupled system to a more robust, decoupled architecture built on PyTorch, and the strategies implemented for fair job scheduling and efficient model management.
Who should watch
- AI Engineers
- Product Managers
- Infrastructure Engineers
- Builders working on scaling AI products
- Those interested in managing large-scale GPU deployments
- Anyone facing challenges with rapid user growth and compute resource management
Key takeaways
- Luma AI's Dream Machine model experienced overwhelming demand, requiring a 10x increase in GPU resources within hours of launch.
- The initial serving stack, based on Triton inference server, proved brittle and ill-suited for multi-GPU, multi-node video model inference across diverse chipsets.
- A rearchitected, decoupled serving stack using vanilla PyTorch on various chipsets (Nvidia, AMD, Groq) offered greater flexibility and easier development.
- Strategies like a dispatch limitation system and SLO-based fair scheduling were developed to manage backpressure and prevent work starvation across different user tiers.
- Model management relies on a versioned model repository in object storage, allowing for reproducible environments and on-the-fly updates without restarts.
- Scaling involved dynamically utilizing training clusters, which, while disruptive to researchers, was necessary to meet user demand.
- The company actively partners with chip providers to optimize PyTorch performance on new hardware.
Notable quotes
*We were woefully unprepared for what came next.*
*The KEK W emoji, which has become a cultural staple of Luma over over time, and it was very much the mood at the time.*
*It's the least enjoyable part of working at Luma is managing these cues.*
Unofficial community note. Prefer the recording for nuance.