Senior/Machine Learning Engineer - Performance Optimization

Role Hybrid in Redwood City, CA. PubMatic is the leading AI-powered ad tech company delivering measurable advertising performance through an intelligent, unified platform that connects buyers, publishers, data partners, and commerce media across CTV, mobile app, and omnichannel environments. About the Role We are looking for a Machine Learning Engineer to help build and improve performance optimization models for PubMatic’s Activate platform. This role is focused on applying machine learning, data analysis, feature engineering, model training, experimentation, and production ML techniques to improve advertiser outcomes across performance advertising goals such as CTR, VCR, CPC, CPA, and ROAS. What You'll Do Build, train, evaluate, and improve machine learning models for prediction, ranking, campaign optimization, bidding, forecasting, and calibration. Work with large-scale datasets from auctions, impressions, clicks, video events, conversions, users, context, inventory, campaigns, and marketplace feedback. Develop and improve features, training datasets, labels, and evaluation workflows for performance advertising models. Analyze model performance across offline metrics, online experiments, campaign outcomes, and business KPIs. Help improve models for CTR, CVR, VCR, CPA, ROAS, app-install, user-value, and campaign-performance optimization. Work with senior ML engineers to improve calibration, model monitoring, experimentation, and production feedback loops. Debug model-quality issues related to feature quality, label quality, sparse conversions, attribution noise, delayed feedback, data freshness, or online/offline metric mismatch. Collaborate with performance advertising signal engineers to use model-ready features, labels, attribution windows, and feedback loops effectively. Partner with engineering teams to deploy models into production decisioning systems and monitor their impact. Work cross-functionally with product, analytics, platform, and business teams to understand campaign performance problems and translate them into ML work We’d Love for You to Have 3+ years of experience building machine learning, data science, ranking, prediction, recommendation, optimization, or large-scale data systems. Strong understanding of core ML concepts such as supervised learning, classification, regression, ranking, calibration, feature engineering, model evaluation, and experimentation. Experience training, evaluating, and improving production-oriented ML models. Experience working with large datasets using SQL, Spark, Python, or similar tools. Strong programming skills in Python, Java, Scala, Go, C++, or similar languages. Ability to reason about model quality, data quality, business impact, and production tradeoffs. Comfort working with ambiguous data problems and iterating through analysis, modeling, experimentation, and production deployment. BS or MS degree in Computer Science, Machine Learning, Statistics, Mathematics, Engineering, or a related technical field, or equivalent practical experience. Preferred Qualifications Experience in ads, search, recommendations, marketplaces, e-commerce, fintech, pricing, forecasting, bidding, or real-time optimization systems. Experience with CTR/CVR prediction, conversion modeling, campaign optimization, bid optimization, forecasting, calibration, or user-value modeling. Familiarity with programmatic advertising, ad serving, attribution, pacing, identity, performance advertising, or real-time bidding. Experience with TensorFlow, PyTorch, XGBoost, LightGBM, Spark ML, or similar ML frameworks. Experience with A/B testing, online experimentation, model monitoring, or production ML observability. Experience working with sparse labels, delayed feedback, biased datasets, or noisy attribution. Experience working cross-functionally with product, engineering, analytics, or business stakeholders. Benefits Our benefits package includes paid leave programs, paid holidays, healthcare, dental and vision insurance, disability and life insurance, commuter benefits, physical and financial wellness programs, unlimited DTO in the US, reimbursement for mobile, and fully stocked pantries plus in-office catered lunches 5 days per week. Diversity and Inclusion PubMatic is proud to be an equal opportunity employer; we don’t just value diversity, we promote and celebrate it. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. Compensation Disclosure In accordance with applicable law, the salary range provided is PubMatic’s reasonable estimate of the total compensation for this role. New hires and current team members are typically compensated toward the middle of our pay range. The actual amount may vary, based on non-discriminatory factors such as location, experience, knowledge, skills, and abilities. In addition to salary PubMatic also offers a bonus, restricted stock units, and a competitive benefits package. Total Compensation Range $260,000 – $330,000 USD #J-18808-Ljbffr PubMatic