Backend/Platform Engineer

Responsibilities

• Design and build production APIs for SGLang and Miles including REST/gRPC endpoints and client SDKs
• Implement authentication, authorization, and rate limiting systems for multi-tenant deployments
• Build control plane infrastructure for job scheduling, resource allocation, and 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
• Debug production issues and implement reliability improvements

Requirements

• 4+ years experience building production backend systems, APIs, or platform infrastructure
• Bachelor's or Master's degree in Computer Science, Engineering, or equivalent industry experience
• Strong proficiency in Python, Go, or Rust
• Experience designing and building REST/gRPC APIs at scale
• Solid understanding of distributed systems, databases, caching, and message queues
• Experience with authentication, authorization, rate limiting, and multi-tenancy
• Familiarity with cloud platforms (AWS, GCP, Azure) and Kubernetes
• Experience with monitoring and observability tools (Prometheus, Grafana, DataDog)

Preferred Qualifications

• Understanding of ML serving infrastructure or high-throughput systems

About the Company

RadixArk is an infrastructure-first company built by engineers who've shipped production AI systems, created SGLang, and developed Miles. We're on a mission to democratize frontier-level AI infrastructure by building world-class open systems for inference and training.