Full Stack Engineer

Full Stack Engineer

Palo Alto, CA

About The Role

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.

Requirements

Technical Excellence

• 4+ years of professional full stack engineering experience
• Based in Palo Alto, CA (Hybrid) / Remote (U.S.)
• Deep experience in:
• Frontend: React / Next.js / TypeScript
• Backend: Python (FastAPI / Django) or Node.js
• RESTful and/or gRPC API design
• Strong understanding of distributed systems concepts
• Experience building systems that handle real-time streaming or high-throughput workloads
• Strong database design skills (Postgres, Redis, etc.)
• Familiarity with containerized environments (Docker, Kubernetes)
• Strong software engineering fundamentals: testing, CI/CD, version control, design reviews

Bonus (High Impact)

• Experience building developer tools or infrastructure platforms
• Experience in ML infrastructure, model serving, or AI tooling
• Familiarity with observability stacks (Prometheus, Grafana, OpenTelemetry)
• Experience with WebSockets or streaming architectures
• Performance optimization at scale
• Experience building internal platforms used by engineers

Responsibilities

You will own end-to-end product surfaces across our developer platform:

• Design and implement high-performance web applications for AI infrastructure tooling
• Build scalable backend systems that interact with distributed inference and training services
• Architect APIs and service layers that serve enterprise and research customers
• Develop observability dashboards, experiment tracking UIs, and performance analytics tools
• Optimize real-time streaming interfaces for model inference workflows
• Work closely with ML engineers and infra teams to expose complex systems through intuitive product surfaces
• Lead architectural decisions for frontend-backend communication, state management, and performance tuning
• Ship production-grade features in fast iteration cycles

You will not just "write UI." You will build the control plane for frontier AI systems.

Your work will directly power:

• Large-scale LLM inference systems
• Reinforcement learning training platforms
• Evaluation and experimentation frameworks
• Developer-facing AI infrastructure products

This is not CRUD dashboard engineering. This is building the operating system for AI builders.

About RadixArk

RadixArk is an infrastructure-first company built by engineers who've shipped production Al 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 Al 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 Al companies and research labs. We're backed by well-known infrastructure investors and partner with NVIDIA, Google, AWS, and frontier Al labs. Join us in building infrastructure that gives real leverage back to the Al community.

Compensation

We offer competitive compensation with equity, comprehensive health benefits, and flexible work arrangements. Compensation is determined by location, level, and experience.

Equal Opportunity

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.