Member of Technical Staff — Backend/API Platform

<div data-page-id="R5pEdqmJmoX3WtxIJiNjDTCKpUb" data-lark-html-role="root" data-docx-has-block-data="false"> <h3 class="heading-3 ace-line old-record-id-IdxIdWSMyoqD4TxNEYpjwCiDpQe">About the Role</h3> <div class="ace-line ace-line old-record-id-RCDod239Zo8KBZxH3wZjB3TUp1f">RadixArk is looking for a Member of Technical Staff — Backend/API Platform Engineer to build the API layer, control plane, and platform services that power SGLang and Miles in production. You'll design and implement the REST/gRPC APIs, authentication systems, multi-tenancy isolation, and monitoring infrastructure that thousands of developers and companies rely on. This role bridges high-performance inference/training systems with production-grade platform engineering.</div> <h3 class="heading-3 ace-line old-record-id-PNQ0dhVtqouI29xSCxPjofzMpje">Requirements</h3> <ul class="list-bullet1"> <li class="ace-line ace-line old-record-id-Eiihd6nU7oUX3UxOg3cjeMESpld" data-list="bullet"> <div>4+ years experience building production backend systems, APIs, or platform infrastructure</div> </li> <li class="ace-line ace-line old-record-id-XYQQdWbb6oOmz9xzJtMjLLB1pJe" data-list="bullet"> <div>Bachelor's or Master's degree in Computer Science, Engineering, or equivalent industry experience</div> </li> <li class="ace-line ace-line old-record-id-EmRSdMYDWoQWP1xbYdMj8wFhppb" data-list="bullet"> <div>Strong proficiency in Python, Go, or Rust with production-quality code standards</div> </li> <li class="ace-line ace-line old-record-id-MZKXdfn9No00PcxiXMOjbbYpp3c" data-list="bullet"> <div>Experience designing and building REST/gRPC APIs at scale</div> </li> <li class="ace-line ace-line old-record-id-SGvadeTUTodQwTxmbMajSKQRpWb" data-list="bullet"> <div>Solid understanding of distributed systems, databases, caching, and message queues</div> </li> <li class="ace-line ace-line old-record-id-M2uAd86XDogv4LxbfR9js1iWp8e" data-list="bullet"> <div>Experience with authentication, authorization, rate limiting, and multi-tenancy</div> </li> <li class="ace-line ace-line old-record-id-LSJ7d2xreoQn7yxTM1ajdvqqpYL" data-list="bullet"> <div>Familiarity with cloud platforms (AWS, GCP, Azure) and Kubernetes</div> </li> <li class="ace-line ace-line old-record-id-GXImd4spnooU6Yxs4l5jRG8Upsb" data-list="bullet"> <div>Experience with monitoring and observability tools (Prometheus, Grafana, DataDog)</div> </li> <li class="ace-line ace-line old-record-id-RpkVdjqEJoGFMLxZGoBjRvblped" data-list="bullet"> <div>Understanding of ML serving infrastructure or high-throughput systems is a plus</div> </li> </ul> <h3 class="heading-3 ace-line old-record-id-QRJ6dESr4o0h2WxRCBtjdgQ4pqb">Responsibilities</h3> <ul class="list-bullet1"> <li class="ace-line ace-line old-record-id-VZ6tdmktcoSXVsx9b58jariqpFz" data-list="bullet"> <div>Design and build production APIs for SGLang and Miles: REST/gRPC endpoints, client SDKs, API versioning</div> </li> <li class="ace-line ace-line old-record-id-AiqodVosOoOCrKxZh4YjXTtApHh" data-list="bullet"> <div>Implement authentication, authorization, and rate limiting systems for multi-tenant deployments</div> </li> <li class="ace-line ace-line old-record-id-IyR7drVF9oorY7xdW6tjC1DJpag" data-list="bullet"> <div>Build control plane infrastructure: job scheduling, resource allocation, model deployment management</div> </li> <li class="ace-line ace-line old-record-id-HDSsd8WBhoeh8ixTZ9WjC2e9pie" data-list="bullet"> <div>Create monitoring, logging, and observability systems for production inference and training workloads</div> </li> <li class="ace-line ace-line old-record-id-Eqb1do0Gwod4RixiCEqjyKs1pZe" data-list="bullet"> <div>Design and implement billing integration, usage tracking, and quota management</div> </li> <li class="ace-line ace-line old-record-id-EhAzd1K1ooC540xtksPjVVXlpTb" data-list="bullet"> <div>Build management dashboards and admin tools for cluster operations</div> </li> <li class="ace-line ace-line old-record-id-UoKcdj6apoxlfNxAPF5jf9qgpnf" data-list="bullet"> <div>Ensure API reliability, performance, and security at scale</div> </li> <li class="ace-line ace-line old-record-id-RGqcdf8eeoBHGixra81jqZPIpIb" data-list="bullet"> <div>Implement multi-tenancy isolation and security boundaries</div> </li> <li class="ace-line ace-line old-record-id-CU25dCrdfojcPlxYRv8jl64Lpic" data-list="bullet"> <div>Create deployment automation, CI/CD pipelines, and rollback procedures</div> </li> <li class="ace-line ace-line old-record-id-PfQwdhSQnosCH2xZxfgjtKCFpjc" data-list="bullet"> <div>Write comprehensive API documentation and integration guides</div> </li> <li class="ace-line ace-line old-record-id-VINRdSK7IokjVlx7yOSjp32rp4g" data-list="bullet"> <div>Partner with Systems Engineers to optimize end-to-end latency from API → serving layer</div> </li> <li class="ace-line ace-line old-record-id-GHgpdRDW5oFCMBxoDc0jP4rjpGe" data-list="bullet"> <div>Debug production issues and implement reliability improvements <div data-page-id="R5pEdqmJmoX3WtxIJiNjDTCKpUb" data-lark-html-role="root" data-docx-has-block-data="false"> <h3>About RadixArk</h3> <p>RadixArk is an infrastructure-first company built by engineers who've shipped production AI systems, created SGLang (30K+ GitHub stars, the fastest open LLM serving engine), and developed Miles (our large-scale RL framework). Founded by AI infrastructure veterans from xAI and NVIDIA, we're on a mission to democratize frontier-level AI infrastructure by building world-class open systems for inference and training. Our team has optimized kernels serving billions of tokens daily, designed distributed training systems coordinating 10,000+ GPUs, and contributed to infrastructure that powers leading AI companies and research labs.</p> <h3>Compensation</h3> <p>We offer competitive compensation with equity, comprehensive health benefits, and flexible work arrangements. Compensation is determined by location, level, and experience.</p> <h3>Equal Opportunity</h3> <p>RadixArk is an Equal Opportunity Employer and is proud to offer equal employment opportunity to everyone regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity, veteran status, and more.</p> </div> </div> </li> </ul> </div>