Software Engineer, Platform

The open AI evaluation platform redefining how the world’s leading AI labs measure model performance is looking for a Software Engineer, Platform to help shape the future of how the world measures artificial intelligence.

They are building an AI gateway that gives developers access to multiple model providers through a unified endpoint. The product is in a private, gated launch, with additional platform capabilities-including direct model access-being built next.

You’ll help build the platform infrastructure that turns their research advantage into enterprise products. This is a founding role on the developer team. You’ll work directly with the founders and early customers to define what they build and how they build it., * Build and scale hands-on backend platform services for client’s AI gateway, evolving an existing prototype into a reliable, independently scalable service.

• Solve hard streaming problems. Handle SSE/streaming responses across heterogeneous providers, including partial failure recovery, mid-stream fallback, and consistent response normalization.
• Ship reliable platform infrastructure, including capabilities such as authentication, rate limiting, usage metering, and cost tracking as the gateway matures.
• Build deep observability. Instrument the platform with distributed tracing, latency breakdowns, usage tracking, and real-time dashboards so customers (and the team) can see exactly what’s happening.
• Build AI-centered platform capabilities. Integrate with client’s evaluation platform and data, and collaborate with research and product teams to turn new ideas into reliable product features.
• Flex across the stack. Contribute to the backend of the company’s Leaderboards and Evals products when needed, working across platform and product boundaries.

• 5+ years of professional software engineering experience, focused on backend services, distributed systems, or developer-facing platforms.
• Strong Golang experience is required. You have built and operated meaningful backend systems in production.
• Experience designing reliable APIs, service integrations, or gateway/proxy-style systems.
• For Senior candidates: a track record of owning and delivering important backend functionality end to end.
• For Staff candidates: extensive backend/platform experience, strong technical judgment, and the ability to provide hands-on technical leadership.
• Cloud experience with GCP, AWS, Azure, or another major provider is helpful but not required.
• Comfortable working hands-on in a fast-moving environment where the product and infrastructure are still evolving.
• Able to work from our San Francisco office three days per week.

Nice to Have

• API gateway, proxy, or multi-provider integration experience.
• Experience with streaming APIs, response normalization, or resilient distributed systems.
• Exposure to LLM APIs, model serving, AI infrastructure, or evaluation platforms.
• Cloud infrastructure experience across GCP, AWS, Azure, Kubernetes, Terraform, Postgres, or Redis.
• Experience building usage tracking, billing/metering, authentication, or developer tooling.

Their openings span more than one career level. The starting salary for this role is $200k and could range up to $350k USD, plus equity. The provided salary depends on many factors, such as work experience and transferable skills, business needs and impact, and market demands., * Comprehensive health, dental, vision, and additional support programs.

• The opportunity to work on cutting-edge AI with a small, mission-driven team.
• A culture that values transparency, trust, and community impact.
• Visa sponsorship available.

This fast-growing startup is building technology that helps people better understand how AI models perform in real-world settings. Its open evaluation platform provides researchers, developers, and organizations with meaningful insights into model quality and performance.

Through crowdsourced benchmarks and human preference data, the company helps inform important decisions about the development and use of artificial intelligence. Its evaluation tools and leaderboards have become trusted resources within the AI community.

Behind the platform is a team of experienced researchers, engineers, and builders who seek truth, move quickly, and care deeply about craftsmanship and impact. They’re building a company where deep expertise meets curiosity and where the work genuinely matters.