Head of Finance

Sieve is an AI research lab building the world's highest-quality multimodal datasets — spanning video, audio, images, text, and 3D. We combine exabyte-scale data infrastructure, novel multimodal understanding techniques, and dozens of proprietary data sources to develop datasets that push the frontier of foundation models. Video alone makes up 80% of internet traffic, and across modalities, data has become the enabling medium powering creativity, communication, gaming, AR/VR, and robotics. Sieve exists to solve the biggest bottleneck in the growth of these applications: high-quality training data. We've partnered with the world's top AI labs and did $XXM last quarter alone, as a team of just ~25 people. We also raised our Series A from Tier 1 firms such as Matrix Partners, Swift Ventures, Y Combinator, and AI Grant. Why Now Sieve is one of the most capital-efficient teams in AI — roughly 25 people serving the world's leading AI labs across every major data modality. You'll join early, own problems end-to-end, and watch your work ship directly into the models defining the frontier. About the Role You’ll be Sieve’s first finance leader, owning the financial foundation for our next stage of growth and helping build the finance function from scratch. This role will own financial planning, infrastructure, and reporting while developing a detailed understanding of Sieve’s unit economics. You’ll help make better decisions across customer deals, compute commitments, contributor payouts, hiring, and capital allocation. You’ll be equally comfortable building detailed models, working across messy operational datasets, and turning your analysis into clear recommendations. What You’ll Do Build and own Sieve’s financial model, forecasts, budgets, and runway planning Model the true cost and margin of customer deals across reinforcement learning, computer use, video, and other data types Partner with leadership on pricing, resource allocation, hiring plans, compute strategy, and other strategic decisions Model and optimize contributor payouts to balance supply, quality, speed, and margin Own financial reporting for the leadership team and board Work across commercial, engineering, and operations teams to improve financial visibility and operating efficiency Own treasury, monthly close, payroll, tax while helping build the finance team Requirements 6+ years of experience in strategic finance, FP&A, investment banking, private equity, or a similarly analytical role Strong financial modeling skills and a rigorous understanding of unit economics, contribution margin, and cash flow Built up a tech finance function before, or at least major parts of one, from scratch. Comfortable operating with significant ownership and ambiguity in a fast-moving startup Excellent communication skills and experience partnering with senior leadership Experience working with a modern finance stack + AI tooling In-person at our SF HQ Nice to Have Experience at an AI, infrastructure, data, marketplace, or usage-based software company Experience modeling compute, storage, or other variable infrastructure costs Experience as an early finance hire at a startup and built teams from scratch Benefits 401k + Full Health Insurance Breakfast, Lunch, and Dinner covered and your choice of snacks Ubers covered home #J-18808-Ljbffr Sieve, Inc.