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# Justin Castilla
Developer advocate at Flox focused on deterministic builds and environments.

## About

Justin Castilla works on developer advocacy at Flox, focusing on declarative environments and reproducible builds. He helps teams solve the complexities of modern software pipelines, making sure builds produce the exact same result across laptops, CI runners, and remote sandboxes.

He explores how deterministic environments—built on Nix—can pin packages and toolchains bit-for-bit across a project's lifecycle. He shows developers how to manage these environments practically, without the steep learning curve.



## Past Sessions

### World Congress 2026 North America · September 23, 2026
San José, CA
- [One Environment, N Machines: Deterministic Builds for Humans and Agents](https://www.wearedevelopers.com/videos/100579-one-environment-n-machines-deterministic-builds-for-humans-and-agents) · 5 min · 🎥 Watch recording



## Videos

- [One Environment, N Machines: Deterministic Builds for Humans and Agents](https://www.wearedevelopers.com/videos/100579-one-environment-n-machines-deterministic-builds-for-humans-and-agents) · Justin Castilla