Software Engineer, Frontier Data Products

Machine Learning Engineer – Frontier Data ProductsLocation: San Francisco, CA or New York City, NYCompany Stage of Funding: Series C (Profitable, $10B Valuation)Office Type: Onsite (5 Days/Week)Salary: $130,000 – $500,000 + Equity + Performance BonusCompany DescriptionOur client is one of the fastest-growing AI infrastructure companies, building the human intelligence platform powering the next generation of frontier AI models. Their platform enables leading AI labs and enterprises to access expert knowledge at scale, accelerating the development of advanced AI systems through high-quality human feedback and evaluation.As a profitable Series C company with a multi-billion-dollar valuation, they are building foundational infrastructure at the intersection of machine learning, human intelligence, and AI product development.What You Will DoDesign and build production machine learning systems that evaluate, validate, and improve AI-generated workDevelop evaluation frameworks for complex tasks where labels are ambiguous, incomplete, or constantly evolvingBuild feedback loops that incorporate human review, disagreement resolution, and model corrections into continuous learning systemsOwn production model performance, including quality, latency, explainability, drift detection, and cost optimizationImprove AI system performance using prompting, retrieval, fine-tuning, heuristics, active learning, and human-in-the-loop techniquesPartner closely with backend engineers to integrate ML inference into scalable production workflowsDebug and improve live production ML systems where model quality directly impacts customer outcomesHelp define the architecture and long-term technical direction of AI evaluation infrastructureIdeal Candidate Background3+ years of experience building and deploying production machine learning systemsStrong software engineering skills with Python and production backend developmentExperience shipping ML systems that measurably improved product or business outcomesStrong understanding of evaluation methodologies, error analysis, and production model behaviorExperience with LLM applications, retrieval systems, model evaluation, or AI-powered productsStrong engineering fundamentals across the full ML lifecycle, from data through deploymentComfortable operating in ambiguous, fast-moving environments with evolving requirementsExcellent communication and cross-functional collaboration skillsPreferredExperience with LLM evaluation, RAG, prompt engineering, fine-tuning, or AI agentsExperience building human-in-the-loop machine learning systemsExperience with Temporal, AWS, PostgreSQL, LiteLLM, or distributed backend systemsFamiliarity with production monitoring, drift detection, and model observabilityStartup or high-growth engineering experienceStrong product instincts and ability to balance ML sophistication with operational simplicityExperience working on AI infrastructure, developer platforms, or ML toolingCompensation and BenefitsCompetitive base salary: $130,000 – $500,000Generous equity packageBi-annual performance bonusRelocation assistanceHousing stipend for employees living near the officeMonthly meal, wellness, and lifestyle stipendsComprehensive medical, dental, and vision coverageOpportunity to build core infrastructure used by the world's leading AI companiesThis is an exceptional opportunity for machine learning engineers who enjoy building production AI systems, solving complex evaluation challenges, and shaping the infrastructure powering frontier AI development.