Senior Machine Learning Engineer - Policy & Safety

The Policy & Safety team sits within Content Platform in the Experience Mission, building the systems that keep our client safe, compliant, and trusted by millions of users and creators. This team owns the content moderation infrastructure — from detection models to policy enforcement systems and compliance data pipelines.

Working at the intersection of machine learning, platform engineering, and regulatory compliance, the team partners closely with Trust & Safety, Legal, and Public Affairs. They’re on the critical path for every new content type and social feature — including messaging, comments, and collaborative experiences — ensuring safety is built in from day one. With a strong focus on “safety by default,” the team is investing in large-scale rearchitecture and ML-driven systems to proactively protect users and empower safer interactions across the platform.

What You Will Do

• Design, build, and ship production-grade machine learning systems that power content safety and policy enforcement at a large scale (specifically the Age Estimation system)
• Own and lead key technical and machine learning deliverables related to migrating this system to a new regression-based approach
• Build robust evaluation frameworks, including standardized datasets, offline and online metrics, and continuous improvement loops
• Drive experimentation to improve model performance, reliability, and fairness in safety-critical systems
• Provide technical leadership within the team, contributing to ML strategy and prioritization
• Represent technical decisions and trade-offs in stakeholder discussions and influence product direction
  
  

Who You Are

• You have solid experience building and deploying machine learning systems in production environments at scale using Python
• You are experienced with training, evaluating, and maintaining ML models using modern frameworks such as PyTorch
• You have a deep understanding of machine learning evaluation, including dataset design, metrics, and continuous improvement systems
• You know how to design systems that balance performance, reliability, and real-world impact in high-stakes domains
• You care about building safe, responsible, and user-centric ML systems
• You are comfortable working across disciplines, partnering with legal, policy, and product stakeholders
• You have experience leading technical projects and influencing direction within a team or product area
• You have experience with distributed systems or backend technologies (e.g., Scala)
  
  

Start/End: 2026-06-08 to 2026-12-07

Workplace: Stockholm/Sweden