People & Talent Lead

About RadixArkRadixArk is a seed-stage AI infrastructure company moving fast and building at the frontier. We're built by engineers who've shipped production AI systems at scale - creators of SGLang (20K+ GitHub stars, the fastest open LLM serving engine) and Miles, our large-scale RL framework. Our team has optimized kernels serving billions of tokens daily, designed distributed training systems coordinating 10,000+ GPUs, and contributed to infrastructure powering leading AI companies and research labs worldwide. We're backed by well-known investors in the infrastructure space and partner with Google, AWS, and frontier AI labs - on a mission to democratize frontier-level AI infrastructure thr†ough world-class open systems for inference and training. We're a lean, scrappy team and we move with urgency - if you thrive in environments where speed and ownership matter, this is the place for you.The RoleWe're looking for a People & Talent Lead to build our People and Recruiting function from the ground up. This is a true 0-to-1 role - you won't be inheriting a playbook, you'll be writing it. You'll own the full recruiting lifecycle across engineering, research, and AI roles, while simultaneously standing up the HR operations, compensation, benefits, and people analytics infrastructure that will carry us through the next phase of growth.You'll report directly to the Head of Finance & Operations and work in close partnership with the founders. This is a rare opportunity to define what "great" looks like for People at RadixArk - and to build it yourself.This role is not for the faint of heart. We move fast, operate with a sense of urgency, and expect the same from everyone on the team.What You'll OwnRecruitingFull-cycle recruiting for engineering, research, and AI roles - from sourcing and outreach to offer and closeSourcing strategy - proactively building pipelines through LinkedIn, referrals, university networks, and creative outreachCandidate experience - managing communication and keeping candidates warm and engaged throughout the processRecruiting ops - owning our ATS, tracking pipelines, and reporting on hiring metricsPeople OperationsHR operations - onboarding, offboarding, maintaining employee records, and building lightweight but scalable HR processesCompensation & offers - designing our comp philosophy, building salary bands, and owning the offer process end to endBenefits - selecting and managing our benefits programs and vendors as we scalePeople analytics - building the reporting and dashboards that give leadership visibility into headcount, hiring velocity, and workforce trendsCompliance & Legal CoordinationCoordinating with legal on immigration, compliance, and employment matters (H-1B, O-1, etc.)Who You Are5+ years of full-cycle recruiting experience, with meaningful time at a startup or high-growth tech companyYou've hired for technical and research roles (engineers, ML researchers, etc.) and know what great looks likeExperience standing up or significantly building out a People function - you've done more than just recruitComfortable owning comp, benefits, and HR ops, not just the top of funnelScrappy, resourceful, and highly responsive - you treat recruiting like a competitive sportStrong organizational skills and able to juggle multiple open roles and operational workstreams simultaneouslyLow ego, high output - you do what it takes to get the right people in the door and keep them thereExperience with immigration processes (H-1B, O-1) a strong plusWhy JoinGround floor opportunity to build the People function at a well-funded, fast-moving AI companyReport directly to the Head of Finance & Operations and partner closely with the foundersReal ownership - you're not inheriting someone else's system, you're building the one everyone will useCompetitive compensation and equity