# Monarch - Single-Machine DevX at Distributed Scale

PyTorch Conference North America 2026 · [All sessions](https://sessionize.com/api/v2/s2rq62nk/view/markdown)

- **Session ID:** 1255147
- **When:** Tuesday, October 20, 2026 11:10 am - 11:35 am (Pacific Standard Time, UTC-08)
- **Room:** LL20C (Lower Level)
- **Speakers:** Thomas Wang, Zach DeVito

## Description

A developer’s computer is part of their identity; as unique as a fingerprint. People have their favorite tools, libraries, and agents set up for their own productivity (and happiness!). New projects that run locally are productive to work in. Unfortunately, as projects scale, we trade this development experience for more compute, using clusters with worse ergonomics.

Monarch is a library for programming an entire cluster as if it were a single machine. Imperative APIs launch processes across the cluster that communicate with fast actor-based IPC and transfer data using RDMA. This fabric lets us provide services that make it feel like all processes across the cluster are on your local machine. For instance, we use Monarch to build filesystem mounts so the local filesystem is broadcast to the entire cluster, and remote logs appear locally.

Iterating with Monarch takes seconds rather than minutes. Debugging is easier: the distributed process exits like a local process and its outputs are visible locally. This speeds up the development loop for humans and agents.

This talk will demo the experience and show how to use Monarch primitives to build large scale post training frameworks.

## Speakers

- [Thomas Wang](https://sessionize.com/api/v2/s2rq62nk/view/markdown/speaker/f51d4db4-100b-4431-ace7-2621f62c483c) — Software Engineer, Meta
- [Zach DeVito](https://sessionize.com/api/v2/s2rq62nk/view/markdown/speaker/6958d047-b51e-42a3-8089-7fa4ad55c8f1) — Meta