# Principal Machine Learning Engineer, Alt Defense at Roblox

- Company: Roblox
- What the company does: Roblox is a global platform where millions of people gather together every day to imagine, create, and share experiences with each other in immersive, user-generated 3D worlds. Backed by Greylock, a16z and Index.
- Company website: https://about.roblox.com/
- Type: Startups (AI role)
- Level: Principal and up
- Location: San Mateo, CA, United States
- Work setup: On-site
- Posted: 2026-09-09
- Apply by: 2026-10-24
- Apply: https://careers.roblox.com/jobs/8187377?gh_jid=8187377
- Page: https://www.1752.vc/careers/jobs/roblox-principal-machine-learning-engineer-alt-defense/

## About the role

A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone.

## What they're looking for

- MS or PhD degree in Computer Science, Machine Learning, or a related field
- 10+ years of industry experience in Applied ML, with a significant focus on anti-abuse, fraud, integrity, or identity
- Expertise in Graph Learning: Deep experience with Large-scale GNNs (GraphSAGE, PGB, etc.) and unsupervised/semi-supervised clustering at the scale of billions of nodes
- Proven track record of leading complex technical projects from conception to production-level deployment
- Experience with high-throughput systems: You understand the nuances of deploying ML models in low-latency environments where "time-to-detect" is a critical KPI
- Adversarial mindset: You can think like a bad actor to anticipate how they will circumvent detection and build robust defenses against it

Tags: Software Engineering