Backend/Platform Engineer

RadixArk is an infrastructure-first company focused on building world-class open systems for AI. They are seeking a Backend/Platform Engineer to design and implement critical API layers and platform services that support their production systems.

Responsibilities:

• Design and build production APIs for SGLang and Miles: REST/gRPC endpoints, client SDKs, API versioning
• Implement authentication, authorization, and rate limiting systems for multi-tenant deployments
• Build control plane infrastructure: job scheduling, resource allocation, model deployment management
• Create monitoring, logging, and observability systems for production inference and training workloads
• Design and implement billing integration, usage tracking, and quota management
• Build management dashboards and admin tools for cluster operations
• Ensure API reliability, performance, and security at scale
• Implement multi-tenancy isolation and security boundaries
• Create deployment automation, CI/CD pipelines, and rollback procedures
• Write comprehensive API documentation and integration guides
• Partner with Systems Engineers to optimize end-to-end latency from API → serving layer
• Debug production issues and implement reliability improvements