Software Engineer, Model Routing & Inference

Our mission is to automate coding. The first step in our journey is to build the best tool for professional programmers, using a combination of inventive research, design, and engineering. Our organization is very flat, and our team is small and talent dense. We particularly like people who are truth-seeking, passionate, and creative. We enjoy spirited debate, crazy ideas, and shipping code.

About the Role

As a Software Engineer on the Model Routing & Inference team at SpaceXAI, you'll build the inference platform that powers every AI interaction in the product.

This team owns the full inference path: making Cursor's AI faster, more reliable, and more cost-effective at a scale few teams in the world get to operate at. Every agent session, every tab completion, and every chat message flows through your stack.

Example projects include...

• Building and evolving our inference gateway, a single abstraction over every provider's API semantics, so model onboarding becomes a config change.

• Designing intelligent cross-provider failover so no single provider outage causes user-visible degradation.

• Designing routing backpressure and admission control so traffic spikes don't cascade into providers.

You may be a fit if

• You have deep experience building high-throughput, low-latency distributed systems, especially in inference serving, traffic routing, or real-time data pipelines.

• You're comfortable reasoning about cost/performance tradeoffs at scale (GPU utilization, provider economics, capacity planning).

• You have strong software engineering fundamentals and enjoy shipping production systems that handle millions of requests.

• You make good calls in the gray area: weighing reliability, cost, latency, and user experience when there isn't a single "right" answer.

Applying

If there appears to be a fit, we'll reach to schedule 2-3 short technicals. After, we'll schedule an onsite in our office, where you'll work on a small project, discuss ideas, and meet the team.

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