Senior Machine Learning Engineer – Ranking

### Company Overview QuinStreet is a pioneer in powering decentralized online marketplaces that connect searchers and consumers with brands. We utilize AI-driven matching technologies to enhance consumer experiences and optimize brand targeting. ### Job Overview Join us to shape how users discover and interact with our marketplace. As a Senior Machine Learning Engineer, you will advance algorithms for ordering, prioritization, and personalization, focusing on ranking systems that balance user satisfaction, business goals, and system health. ### Responsibilities - Design and improve ranking systems through rigorous measurement and experimentation. - Translate broad goals into clear metrics and deliver validated gains. - Advance evaluation practices and help teams make evidence-based decisions. - Build high-value signals and features with reliable offline/online pipelines. - Incorporate content understanding signals such as text, image, and metadata. - Make uncertainty-aware decisions and manage model stability over time. - Collaborate with Engineering, Product, Business, and Analytics teams to deliver resilient solutions. ### Requirements - Advanced degree (MS/PhD) in CS, Statistics, or related field, with 3+ years post-PhD or 5+ years of industry experience. - Strong foundations in applied ML, statistics, and optimization with demonstrated impact in ranking/recommendations. - Proficiency in Python and solid software engineering practices (testing, CI/CD). - Experience with large-scale datasets and latency-sensitive production ML. - Excellent communication and cross-functional collaboration skills. ### Preferred Qualifications - Proven success in delivering production-grade ranking systems with measurable business impact. - Experience building feature/signals pipelines and observability for ML systems. - Familiarity with monitoring, calibration, and adaptive learning techniques. - Proficiency in SQL and knowledge of Linear Algebra and Combinatorial optimization is desired.