Full Stack Engineer
RadixArk is seeking a Full Stack Engineer to build foundational tools for the next decade of AI. This role involves designing and implementing high-performance web applications and scalable backend systems for AI infrastructure tooling, owning end-to-end product surfaces across their developer platform. The engineer will be crucial in powering large-scale LLM inference, reinforcement learning training, and AI infrastructure products.
RadixArk is building the infrastructure layer for frontier AI systems — unified inference, training, and evaluation stacks powering next-generation LLM applications at scale. Our platform integrates high-performance model serving, RL pipelines, and large-scale distributed systems across GPUs, TPUs, and emerging accelerators. We work at the intersection of systems engineering, AI research, and developer experience. We are looking for a world-class Full Stack Engineer who thrives in high-ambiguity environments and wants to build foundational tools for the next decade of AI.
You will own end-to-end product surfaces across our developer platform:
You will not just “write UI.” You will build the control plane for frontier AI systems.
Your work will directly power:
This is not CRUD dashboard engineering. This is building the operating system for AI builders.
RadixArk is an infrastructure-first company built by engineers who've shipped production AI systems, created SGLang (20K+ GitHub stars, the fastest open LLM serving engine), and developed Miles (our large-scale RL framework). 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. We're backed by well-known infrastructure investors and partner with NVIDIA, Google, AWS, and frontier AI labs. Join us in building infrastructure that gives real leverage back to the AI community.
Posted June 11, 2026