Senior Software Engineer, Build Platform

As a Senior Software Engineer on the Build Platform team, you will build the cloud infrastructure that powers AI-driven creation on Roblox. Build lets anyone make a game by describing it, on mobile and in Studio. Creators can generate a playable experience from a sentence, iterate on it, playtest, and publish. Our team owns the platform underneath: the cloud-hosted agent harness, tools and skills, and evaluation framework.

You'll work on the systems that make agents run well at scale: long-running workflow orchestration, model integration and routing, tool execution, sandboxed game sessions, evals, and the observability, safety, and cost controls that let us ship to millions of creators.

• Design, build, and operate services in the agent platform, including orchestration, session management, model routing, and tool/skill execution.
• Improve the reliability, latency, and cost of multi-step agent workflows running in production.
• Build and extend evaluation infrastructure so teams can measure quality and catch regressions before they reach creators.
• Partner with Build product teams, ML infrastructure, and Safety to ship new capabilities quickly and safely.
• Participate in on-call and help raise the bar for operational excellence.
• Write clear technical specs, review code, and mentor other engineers.
• 5+ years of experience building and operating backend or distributed systems in production.
• Proficiency in C#, Java, Go, or a similar language.
• Experience with cloud infrastructure, containerized services, and workflow or job orchestration systems (e.g., Temporal, Kubernetes).
• A track record of owning services end-to-end: design, launch, monitoring, and incident response.
• A BS in Computer Science or a related field, or equivalent professional experience.
• Curious about LLMs and agentic systems, and eager to work on how they behave in production.
• Pragmatic. You ship iteratively and let data and evals guide decisions.
• Experienced building on LLM APIs, agent frameworks, or eval pipelines (bonus).

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