Senior Software Engineer- User Behavior

Every day tens of millions of people come to Roblox to explore create play learn and connect with friends in 3D immersive digital experiences all created by our global community of developers and creators.

At Roblox were building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together from anywhere in the world and on any device. Were on a mission to connect a billion people with optimism and civility and looking for amazing talent to help us get there.

A career at Roblox means youll 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.

You will build the backend systems that fundamentally shift how Roblox responds to unsafe behavior - from reactive stateless punishment to a personalized adaptive system that reflects who a user actually is.

You will own core backend infrastructure for a new capability at Roblox: a low-latency behavioral data layer a centralized rules-and-inference engine and a unified intervention-delivery framework that together let us treat users based on their real risk profile instead of a single point total. This is a rare opportunity to build foundational high-scale systems that directly shape how Roblox understands and responds to risk across hundreds of millions of users.

You will feel a deep sense of responsibility building systems that directly affect millions of users especially minors on one of the worlds largest platforms. Your work will reduce harm improve fairness and help ensure Roblox remains a place where creativity and community can thrive safely.

• Build the User Behavior Foundation: Design and operate the low-latency per-user behavioral data layer that powers real-time safety decisions - aggregating signals like violation history in-game reports and behavioral patterns into a single queryable source of truth.
• Own the Consequence Engine: Build and evolve the centralized decision engine that combines deterministic rules with ML risk signals into a single consistent safety decision the authoritative system every consequence flows through.
• Own the Feature Restriction Platform: Build a unified backend-driven framework for delivering safety interventions that any product team can plug into replacing todays fragmented feature-specific implementations.
• Unify Abuse Reporting: Build the backend that consolidates reporting channels into a single scalable framework - integrating LLM-based classification agentic review workflows and ML models to improve report routing prioritization and reporter feedback while meeting global regulatory requirements.
• Design for trust and auditability: Build serving infrastructure that meets a high bar for explainability and fairness since these systems directly determine consequences for millions of users.
• Ship code not just designs: Own end-to-end delivery - from system design through migration testing and production operation.

• 5 years of experience building and operating production backend systems at scale ideally in Go or a comparable statically-typed backend language.
• Strong experience designing distributed systems: service APIs (RPC/gRPC) data modeling for high-throughput event ingestion caching and low-latency read paths.
• Experience building and evolving rules engines workflow/decision systems or similarly stateful business-logic services.
• Experience with streaming or batch data pipelines feeding a feature store or similar ingestion layer and comfort partnering with ML engineers who consume that data.
• Solid production operations fundamentals: monitoring alerting oncall capacity planning and incident response for systems with real user-facing impact.
• Nice to have: experience in Trust & Safety fraud risk or other adversarial domains; experience with feature stores or ML-serving infrastructure; experience building frontend-agnostic backend-driven UI frameworks (e.g. server-driven intervention/notification rendering).

• A Systems Thinker: capable of designing infrastructure that other teams (ML feature teams policy) build on top of not just point solutions.
• A Pragmatic Builder: scrappy and impact-oriented comfortable turning scattered undocumented signals and legacy code paths into clean well-owned services.
• Comfortable with Ambiguity: this space is actively being redefined youll help set the standard not just implement one handed to you.
• A Reliability-Minded Engineer: you treat testing migrations and oncall as first-class parts of the job not afterthoughts.
• Committed to Ethical Responsible Engineering: dedicated to building systems that are fair auditable and operate with the utmost responsibility toward user safety.