Senior Director of Engineering, Generative AI

About the Role

Roblox Build is our generative creation product, the platform where creators design, build, and publish 3D experiences. We are looking for a Senior Director of Generative AI to lead the Applied AI organization inside Build, responsible for turning state-of-the-art foundation models into high-quality, reliable creation systems at Roblox scale. This leader will own the full applied AI stack: model strategy and routing, model adaptation and fine-tuning, code generation (CodeGen), 3D layout generation (LayoutGen), and the evaluation science and infrastructure that tells us what actually works.

Responsibilities

• Own model strategy and routing for Build. Design and build an intelligent model layer that selects the right model for each creation task based on quality, capability, latency, cost, and safety, leveraging both frontier models and Roblox-adapted open-source models.
• Lead model adaptation across the Applied AI org, including fine-tuning, distillation, synthetic data generation, human feedback pipelines, and preference optimization for Roblox-specific creation tasks such as Luau code generation and 3D scene understanding.
• Drive CodeGen capabilities forward by building AI systems that understand creator intent, reason across multi-file Roblox experiences, execute tools, and reliably make complex changes to existing games, going well beyond code completion.
• Build LayoutGen intelligence by developing the AI capability that turns a creator's intent into coherent 3D scenes, including object selection, spatial reasoning, placement, aesthetic quality, and iterative editing.
• Own evaluation as a core technical discipline. Build the benchmarks, quality metrics, judge methodologies, experiment infrastructure, and human evaluation pipelines that answer whether model, prompt, or routing changes actually improve creator outcomes.
• Close the feedback loop between model development, evaluation, and production, ensuring that quality signal flows continuously from creator outcomes back into training data, model updates, and release decisions.

Qualifications

Required

• 10+ years of experience in machine learning and AI, with 5+ years in senior technical leadership roles overseeing applied AI or ML engineering organizations that have shipped generative AI systems into production at scale.
• Deep technical grounding across multiple areas of applied AI, including LLM post-training (RLHF, DPO, distillation), model routing and adaptation, agentic systems, code generation, or evaluation science.
• Demonstrated experience building and leading high-performing organizations that span both AI research scientists and production engineers, including hiring, developing talent, and personnel management.
• Strong evaluation fluency, with a track record of building eval frameworks that predict production outcomes, designing benchmarks, and building experiment infrastructure.
• Experience operating cross-functionally across research, product engineering, and platform teams in complex technical organizations.
• Genuine interest in AI-assisted 3D world creation and domain-specific code generation.

Work Policy

• Roles based in the San Mateo office are onsite Tuesday, Wednesday, and Thursday, with optional presence on Monday and Friday.