Senior Machine Learning Engineer, Ads Experimentation & Measurements

The opportunity Unity’s Ads Experimentation Platform team is looking for a senior machine learning engineer to lead the evolution of how we validate and optimize our global advertising ecosystem. At Unity, our ads reach billions of devices, and the ability to rapidly iterate on machine learning models or ads delivery pipelines is critical to our growth. In this role, you will be the technical authority for our experimentation and evaluation roadmap. You will bridge the gap between advanced statistical methodology and large-scale engineering, building the tools that allow ML teams to iterate faster and with higher confidence. You will join a team focused on high-velocity innovation, moving beyond standard A/B testing into the next generation of causal inference and high-sensitivity evaluation methodologies. What you'll be doing Ad Delivery Expertise: Hands-on experience evaluating pacing and ad selection systems, with strong domain knowledge of the ads ecosystem (advertiser objectives, bidding/pricing dynamics, attribution, and marketplace mechanics) and practical familiarity with simulation-based measurement to pre-validate model and policy changes before live deployment. Product Analytics & Insights: Demonstrated ability to drive product decisions through analytics — defining metrics, building measurement frameworks, analyzing A/B test results, and translating experiment o [... source excerpt omitted ...] roduct, and Business partners Advance Experimentation Platform: design the statistical methodologies of our experimentation platform in a complex, budget-constrained environment. You will lead the implementation of variance reduction (CUPED), sequential testing, and interleaving frameworks to maximize sensitivity and accelerate evaluation cycles. You will also build the statistical foundations for automated pipelines that autonomously test and select optimal features and hyperparameters at scale. Define Long-Term Value (LTV) Proxy Metrics: Research and validate surrogate metrics that correlate highly with long-term user retention, churn, and value. You will provide ML teams wit [... source excerpt omitted ...] ment of high-performing models at scale. Cross-Functional Technical Leadership: Serve as the lead subject matter expert on experimentation for ML, Product, and Engineering teams. You will ensure statistical rigor is integrated throughout the product lifecycle, from initial model training to live production auctions. What we're looking for 5+ years of experience in Data Science or Applied Research, specifically within Ad Tech, Marketplaces, or high-scale experimentation platforms. Advanced Education: An MS or PhD in a quantitative field (Statistics, Economics, Computer Science, Operations Research, or equivalent). Deep expertise in causal inference, experimental design, and f