Backend Engineer, Core Services & Auth

Cursor; New York (NY); On-site; USD 140,000 - 225,000; Full time

Benefits offered by this job

Equity

Medical insurance

Vision

Dental coverage

401(k) retirement plan

Short & long-term disability insurance

Life insurance

Employee discounts

Job summary

SpaceXSI is recruiting a Software Engineer for the Core Services team to own the critical shared services that power product surfaces and the infrastructure layer. You will design scalable authentication, build out the agent backend, and create a robust webhook server with reliable delivery and observability.

You will also harden integrations with source control providers and drive end-to-end agent reliability.

Qualifications

• Experience building and operating backend services in production.
• Experience working with APIs and third-party integrations.

Responsibilities

• Own authentication: designing scalable auth architecture for developer tools.
• Powering the agent backend: infrastructure behind Cursor's agent workflows.
• Build a robust webhook server with high-throughput delivery and observability.
• Harden SCM integrations: resilient abstractions over source control providers.
• Drive end-to-end agent reliability: improve path from user action to agent response.

Skills

Auth systems

API gateways

Webhook infrastructure

Agentic products

Reliability

OAuth/JWT/RBAC

Event-driven architectures

Developer-facing platform services

Job description

SpaceXSI is recruiting a Software Engineer for the Core Services team to own the critical shared services that power product surfaces and the infrastructure layer. You will design scalable authentication, build out the agent backend, and create a robust webhook server with reliable delivery and observability.

You will also harden integrations with source control providers and drive end-to-end agent reliability.