Software Engineer, Core Services
Cursor, San Francisco, CA +1
The role
As a Software Engineer on the Core Services team at SpaceXSI, you'll own the critical shared services that sit between our product surfaces and the infrastructure layer: auth, webhooks, and the backend systems that power agent workflows. SpaceXSI is redefining how developers write code, and your work is what makes that possible at scale. You'll build the systems that every product team depends on, ensuring they are reliable, well-abstracted, and ready for whatever comes next.
What you will do
- Own authentication: designing and implementing a scalable auth architecture that secures one of the most widely-used developer tools in the world
- Powering the agent backend: owning the infrastructure behind Cursor's agent workflows, optimizing for end-to-end performance and reliability as agents become central to the developer experience
- Build a robust webhook server: handling high-throughput event delivery with proper retry semantics, dead-letter queues, and observability so external integrations just work