Principal Software Engineer, Build Platform (AI)

Location: San Mateo, California, United States; office-based roles are onsite Tuesday, Wednesday, and Thursday, with optional presence on Monday and Friday.

Annual base salary: $345,040–$399,420 USD, with equity compensation and benefits for full-time employees.

Company

Roblox builds tools and platforms for creating and experiencing 3D digital experiences used by a global community of developers and creators.

What you will do

• Own the technical architecture and long-term roadmap for the Build agent platform.
• Design infrastructure for long-running, multi-step workflows, model integration and routing, tool and skill execution, and sandboxed game environments.
• Build reliability, safety, observability, usage metering, cost-efficiency, and model-routing systems for production AI workloads.
• Define agent-quality metrics and evaluation infrastructure supporting model, prompt, and skill decisions.
• Partner with Build product teams, ML infrastructure, and Safety to ship capabilities safely and quickly.
• Raise engineering standards through design reviews, mentorship, and hands-on technical leadership.

Requirements

• 8+ years of experience building and operating large-scale distributed systems, including technical leadership across multiple teams.
• Deep experience designing backend platforms used by other engineering teams.
• Hands-on production AI/ML experience, including model serving, orchestration, LLM integration, or agentic execution loops such as planning, tool use, recovery, and long-running workflows.
• Strong understanding of tool and skill design and structured evaluation for AI systems.
• Sound judgment for weighing tradeoffs and making pragmatic decisions under ambiguity.
• Clear communication skills for explaining complex technical direction to engineers, product, and leadership.
• BS in Computer Science or a related field, or equivalent professional experience.

Nice to have

• Experience with workflow engines such as Temporal, multi-provider model routing, or AI cost management.

Culture & Benefits

• Full-time employees are eligible for equity compensation and benefits.
• Office-based roles require onsite work Tuesday through Thursday, with optional presence on Monday and Friday unless otherwise noted.
• Roblox provides equal employment opportunities and reasonable accommodations during the recruiting process.
• For US-based roles, Roblox may be unable to employ candidates whose US work authorization relates to certain visa categories or support future H-1B sponsorship at this time.