Skip to content
How Cursor Trained Composer on Fireworks: Distributed Infrastructure for High-Performance RL episode artwork

May 26, 2026 45 min

How Cursor Trained Composer on Fireworks: Distributed Infrastructure for High-Performance RL

from Training Data Hosted by Sequoia Capital

Cursor's Federico Cassano and Fireworks' Dmytro Dzhulgakov explain how they collaborated to build Composer as a specialized foundation model. The core insight: models have finite capacity in their weights, and allocating all those bits to the singular task of software engineering in Cursor frees the model to be both better at the task and far more efficient at inference. Rather than start from pre-training and work up, they took an unconventional top-down approach — mid-training and RL on top of an open-source base to get a useful model into users' hands fast, then specializing the model around real Cursor usage. With Fireworks providing distributed infrastructure, Composer delivers frontier-class coding performance with the speed of a much smaller model. Hosted by Sonya Huang, Sequoia Capital

Episode details come from the podcast's RSS feed.

Embed this episode

Ready to play

How Cursor Trained Composer on Fireworks: Distributed Infrastructure for High-Performance RL

0:00 45:33

No transcript yet.

Requests help us decide what to transcribe next.

Frequently asked questions

How long is this episode of Training Data?

This episode is 45 minutes long.

When was this Training Data episode published?

This episode was published on May 26, 2026.

Can I download this Training Data episode?

Yes. Use the download control on the episode player to save the publisher-provided media file.