Staff Software Engineer - Cloud Infrastructure

Arena is the platform for evaluating how AI models perform in the real world. Founded by researchers from UC Berkeley's SkyLab, we're on a mission to measure and advance the frontier of AI for real-world use, and to build the foundation for everyone to understand, shape, and benefit from it.

Tens of millions of people use Arena each month to evaluate how frontier systems handle the work they actually do. The preferences they share power the most transparent, rigorous, and human-centered evaluations in AI. Leading AI labs, enterprises, and independent researchers rely on our work and open datasets to understand how models behave in real workflows: agentic coding, creative generation, professional productivity, and beyond. We go beyond leaderboards and decompose what human experience reveals about AI, so models advance toward the work people actually do.

We're a team of researchers, academics, builders, and creatives from UC Berkeley, Google, Stanford, and DeepMind. We seek truth, move fast, and value craftsmanship, curiosity, and impact over hierarchy. We're building a company where thoughtful, curious people from all backgrounds can do their best work together, in an office culture that radiates excellence, energy, and focus.

Arena Intelligence is seeking a Cloud Infrastructure Engineer to drive the strategy and execution of the platform that runs Arena. You'll own the infra to enable our apps, API and AI agents, also how the compute, and data pipelines are hosted, connected, and secured across multiple clouds and managed platforms. You'll make the key decisions: where our applications should run, how long-running agent workflows should be executed, and when managed services are worth it versus running our own. Then you'll build it with the team.

As our cloud infrastructure engineer, you'll partner closely with product, research, data, and security to make our platform fast to build on, reliable at scale, and secure by default. You'll set the standards for identity, secrets, networking, and infrastructure-as-code, and you'll help grow the infrastructure team as we scale.

• Own Arena's cloud architecture end to end: hosting, compute, networking, and the infra our products are built on.

• Decide and execute on our hosting and workload strategy, including serverless and edge platforms, containers and Kubernetes, and durable execution for long-running AI agent workflows.

• Build identity and access the right way: workload identity, least-privilege IAM, short-lived credentials, and centralized, audited secrets management.

• Design network boundaries, private connectivity, and egress controls for our databases and services.

• Manage all infrastructure as code with clear ownership, CI/CD, and review practices.

• Establish reliability practices: SLOs, monitoring and alerting, on-call, incident response, and post-incident follow-through.

• Keep infrastructure cost and risk visible, and improve them continuously.

• Help hire and mentor the infrastructure team as we grow.

• 6+ years of experience building and operating production cloud infrastructure, including owning architecture decisions at a fast-growing company.

• Deep hands-on experience with GCP and/or AWS, Kubernetes, and Terraform (or a similar infrastructure-as-code tool).

• Strong experience with cloud identity and secrets at scale: OIDC and workload identity federation, IAM design, secret managers, and key rotation.

• Experience running serverless or edge platforms (e.g. Vercel, Cloud Run, Lambda, Cloudflare Workers) and the judgment to know when to use them.

• Experience with queues, workflow engines, or durable execution systems for long-running and asynchronous workloads.

• A track record of leading infrastructure through incidents and turning lessons into lasting improvements.

• Clear written communication and the ability to explain trade-offs to engineers and leadership.

• Experience building infrastructure for AI products, such as sandboxed code execution, model serving, or GPU clusters.

• Experience with data platforms (Databricks or similar) and Postgres at scale.

• Background in cloud security, detection engineering, or security posture tooling.

• Experience as the first infrastructure hire at a fast-growing startup.