Arena
Software Engineer - Platform
SF Bay Area · On-site · Full-time · Posted Sep 24, 2026
- Experience
- ~5+ years of backend engineering experience, with meaningful time spent on distributed systems, infrastructure, or developer-facing platforms. Senior: proven delivery on meaningful backend work; Staff: extensive, deep experience owning backend systems end to end.
About the job
Build and scale the infrastructure behind Arena’s online AI evaluation systems, including model gateways, APIs, streaming, and serving layers.
What you'll do
- Build low-latency, reliable APIs and handle streaming across model providers, including failure recovery and response normalization.
- Develop enterprise infrastructure and observability, including authentication, usage metering, audit logging, tracing, and dashboards.
- Integrate infrastructure with Arena’s evaluation products and contribute to backend systems for Leaderboards and Evals.
What they ask for
- Strong proficiency in Go.
- Experience with LLM provider APIs and understanding of streaming, token management, rate limits, and model-specific quirks.
- Product-oriented mindset and comfort working in a startup with fluid scope.
Nice to have
- Cloud infrastructure, Kubernetes, Terraform, Postgres, or Redis experience.
- Experience with API gateways, AI/ML infrastructure, enterprise-ready features, billing infrastructure, or modern AI infrastructure tools.
Tools
Go, OpenAI, Anthropic, Google, AWS, GCP, Azure, Kubernetes
AI focus
Build AI gateways and serving infrastructure; integrate with Arena’s evaluation platform, data, and customer-specific benchmarks, and collaborate with research on AI-centered products.
Model-written summary · the original posting is authoritative