Senior Infrastructure Engineer
LMArena
full-time
Posted on:
Location Type: Hybrid
Location: Bay Area • California • 🇺🇸 United States
Visit company websiteJob Level
Senior
Tech Stack
Distributed SystemsJavaScriptNode.jsPostgresTypeScript
About the role
- Own technical strategy for LMArena’s core infrastructure - networking, APIs, services, data systems, and security foundations.
- Design and implement high-performance systems that scale to hundreds of millions of real-time interactions and evaluations per day.
- Collaborate with security engineering to embed anti-abuse measures, Sybil resistance, and trust systems into core platform architecture.
- Partner with product engineering to deliver infrastructure improvements that directly accelerate feature velocity and reliability.
- Build developer-facing primitives and tooling—internal APIs, SDKs, CI/CD enhancements—that make our platform more productive and safe to build on.
- Monitor, profile, and optimize system performance across backend services, databases, and networking layers.
- Drive operational excellence through observability, capacity planning, and incident response best practices.
- Mentor engineers across the company in building scalable, performant, and secure systems.
Requirements
- 8+ years of experience in backend, infrastructure, or systems engineering, including staff-level scope in a high-scale production environment.
- Proven experience designing and operating distributed systems at scale (millions of DAU / billions of requests).
- Deep knowledge of networking fundamentals, service-to-service communication, and traffic routing at scale.
- Hands-on experience with performance profiling, observability, and reliability engineering.
- Track record of collaborating with security and product engineering to deliver both foundational systems and user-facing features.
- Clear communicator who can lead technical discussions, build alignment across teams, and partner with us to prioritize the needs of the business.
- Bonus Points: Experience with Node.js, Typescript, Serverless Environments, Postgres;
- Background in anti-abuse systems, security engineering, or trust & safety platforms; Experience building infrastructure for real-time, user-driven platforms.
Benefits
- Comprehensive health and wellness benefits, including medical, dental, vision, and additional support programs.
- Competitive compensation and equity aligned to the markets where team members are based.
- The opportunity to work on cutting-edge AI with a small, mission-driven team
- A culture that values transparency, trust, and community impact.
Applicant Tracking System Keywords
Tip: use these terms in your resume and cover letter to boost ATS matches.
Hard skills
backend engineeringinfrastructure engineeringsystems engineeringdistributed systemsperformance profilingobservability engineeringreliability engineeringnetworking fundamentalstraffic routinganti-abuse systems
Soft skills
clear communicationtechnical discussionsteam alignmentcollaborationmentoring