About the Role RadixArk is seeking experienced product-focused engineers to join our team in building the developer-facing surfaces of our inference and training infrastructure. As a Member of Technical Staff — Product, you will partner closely with our Product Managers, research scientists, and systems engineers to turn cutting-edge AI infrastructure into delightful, performant, and reliable products that developers and enterprises love to use. You will own end-to-end product experiences across APIs, SDKs, dashboards, playgrounds, and developer tooling that sit on top of SGLang, Miles, and our broader inference and training stack. You'll work at the intersection of frontier systems and great product craft, shaping how developers discover, evaluate, and integrate RadixArk's capabilities into their own AI workloads. If you are excited about translating cutting-edge infrastructure into products that meaningfully shape how the AI community builds, this role is for you. Key Responsibilities Product Engineering & Execution • Collaborate with cross-functional teams (Product, Design, Research, Infrastructure, Developer Relations) to design and ship developer-facing products on top of RadixArk's inference and training platforms. • Build and maintain customer-facing APIs, SDKs, CLIs, dashboards, and playgrounds that expose the power of SGLang, Miles, and our serving infrastructure in intuitive, well-documented interfaces. • Implement custom user interfaces and developer experiences using modern frontend and backend technologies, with a high bar for performance, accessibility, and craft. • Architect efficient and scalable systems that bridge low-level infrastructure (GPU scheduling, model serving, distributed training) with high-level product surfaces. • Analyze and optimize code for quality, efficiency, and performance, and provide thoughtful feedback to peers during code reviews. Technical Leadership & Ownership • Establish end-to-end ownership of components, features, or systems, from initial design through rollout, monitoring, and iteration. • Set direction and goals for product engineering initiatives, lead major launches, and provide technical guidance and mentorship to peers and new team members. • Identify and resolve performance, reliability, and scalability issues across the product stack, and drive efforts to reduce technical debt. • Participate in design reviews and technical discussions, evaluating trade-offs between system complexity, developer experience, and time-to-ship. Partnership with Product & Users • Work hand-in-hand with Product Managers to translate roadmap priorities into well-scoped technical deliverables, surfacing trade-offs and unblocking ambiguity early. • Engage directly with early adopters, design partners, and the open-source community to understand pain points and rapidly iterate on product experiences. • Contribute to technical content (documentation, code samples, blog posts, demos) that helps developers get the most out of RadixArk's products. • Use data, telemetry, and user feedback to validate hypotheses, measure the impact of launches, and inform what to build next. Qualifications Minimum Requirements • Bachelor's degree in Computer Science, Computer Engineering, a relevant technical field, or equivalent practical experience. • 5+ years of software engineering experience building production systems, OR 3+ years with a PhD in a relevant field. • Strong programming skills in at least one of: Python, TypeScript/JavaScript, Go, C++, or Rust. • Demonstrated experience shipping developer-facing or product-facing software end-to-end, including APIs, SDKs, web applications, or developer tools. • Experience using data and analysis to explain technical problems, prioritize work, and inform design decisions. • Excellent collaboration and communication skills, with a track record of driving complex technical projects across teams. Preferred Qualifications • Experience building products on top of AI/ML infrastructure, model serving systems, or large-scale distributed systems. • Familiarity with LLM inference and training stacks (e.g., SGLang, vLLM, TensorRT-LLM, PyTorch, Megatron, DeepSpeed, Ray) and the trade-offs involved in serving and training large models. • Experience contributing to or maintaining open-source projects, especially in the AI/ML or infrastructure ecosystem. • Hands-on experience designing developer experiences such as public APIs, SDKs, CLIs, or dashboards, where developer ergonomics directly drive adoption. • Strong product sensibility, comfortable making thoughtful UX and API design decisions rather than just executing specs. • Experience improving quality through code reviews, testing, careful rollout, monitoring, and proactive iteration. • Demonstrated ability to integrate AI tools into engineering workflows to drive measurable impact (efficiency gains, quality improvements). • Experience working in B2B, developer-facing, or infrastructure product environments. About RadixArk 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. Compensation Depending on background, skills, and experience, the expected annual salary range for this position is $200,000 - $400,000 USD + equity. 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.