Backend Engineer

Arena

Backend Engineer developing API-based products for Arena’s evaluation systems. Collaborating with infrastructure and research teams to design robust data architectures and enterprise-grade backends.

Posted 7/17/2026full-timeBay Area • California • 🇺🇸 United StatesMid-LevelSeniorWebsite

Core Competencies

Role fit

Core Competencies

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Demonstrates expertise in building API-based products and enterprise-grade backends, with a strong focus on data architecture and developer experience. Proficient in modern backend languages, particularly Go, and skilled in data modeling and querying with Postgres.

Highest-signal resume keywords

Backend Engineering ExperienceAPI Design and DevelopmentData Modeling and QueryingProduct-Oriented MindsetComfort with Ambiguity

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills

API DevelopmentBackend DevelopmentData ArchitecturePostgresGo ProgrammingRedisService IntegrationData Pipeline DevelopmentUsage MeteringAuthentication

Soft Skills

Problem-SolvingAdaptabilityCollaborationDeveloper Experience Focus

Tools & Technologies

RBACMulti-TenancyAudit LoggingBilling Integration

Industry Keywords

Enterprise-Grade SystemsStartup EnvironmentData ConsistencyHigh-Reliability APIsScoring Pipelines

Tech Stack

Tools & technologies

GoPostgresRedis

About the role

Key responsibilities & impact

Build API-based products from the ground up. Design and ship the low-latency, high-reliability APIs and services that power Leaderboards, Evals, and Arena data products — clean, versioned, and built for the developers who consume them.
Turn evaluations into product. Partner with the research team to take novel eval methods and make them durable, full-featured products: scoring pipelines, data models, and the APIs that expose them.
Ship enterprise-grade backends. Usage metering, cost attribution, billing integration, authentication, RBAC, multi-tenancy, and audit logging — the systems enterprise customers expect.
Own the data architecture. Unify our public and private evaluation data, design schemas that hold up as the product grows, and make Arena’s data queryable, consistent, and fast.
Flex across the stack. Contribute to the backend of our Leaderboards and Evals platforms when needed, helping unify our public and private data architectures.

Requirements

What you’ll need

5+ years of backend engineering experience, with meaningful time spent on building product facing APIs, services and data systems at scale.
Strong proficiency in a modern backend language — Go preferred — and the judgment to design APIs other engineers and customers will live with for years.
Solid data fundamentals. You’re comfortable modeling, querying, and scaling Postgres, and you know when to reach for Redis, a queue, or a warehouse.
Experience composing services into products — integrating payments, auth, analytics, or data pipelines into something coherent and reliable.
A product-oriented mindset. You think about the developer experience of your APIs, not just the implementation. You ask “why” before “how.”
Comfort with ambiguity. We’re a startup. Scope is fluid, context shifts, and you’ll wear many hats. That should sound exciting, not stressful.

Benefits

Comp & perks

Comprehensive health and wellness benefits, including medical, dental, vision, and additional support programs.
Opportunity to work on cutting-edge AI with a small, mission-driven team.
Culture that values transparency, trust, and community impact.