Sr Machine Learning Engineer

Company: Quantcast
Location: San Francisco
Posted on: February 19, 2026

Job Description:

Job Description Job Description At Quantcast, we don't just build advertising technology, we revolutionize how it works. Our AI-powered Demand Side Platform (DSP) connects the world's most ambitious marketers with their ideal audiences across the open internet, delivering results that actually move the needle. Since 2006, we've been the industry's trailblazer, launching the first AI-powered measurement platform for publishers and the first AI-driven DSP. Our AI doesn't just optimize—it delivers the measurable outcomes that matter most to our clients, giving them the competitive edge they need in a crowded marketplace. Ready to join the team that's defining the future of digital advertising? The Modeling team is responsible for Machine Learning (ML) systems at Quantcast. We build and maintain multiple ML products that price millions of bid requests per second in a real-time auction environment to maximize advertiser outcomes. For each bid our models predict age, gender, viewability, fraud, advertiser relevance and many more characteristics. We are developing novel and effective platforms and algorithms to combine our vast first-party dataset with third-party data to provide the highest quality demographic and behavioral analysis of digital audiences on the market. As a Sr Machine Learning Engineer, you will use our large datasets, computational power, and analytic tools to build high-quality and diverse products to support Quantcast’s position as a leader in advertising. You will help lead our efforts in crafting, implementing, and operating large-scale machine learning systems in a production environment. You care about the health and maintainability of our systems and the velocity of the engineering teams. You explore data, research new algorithms, experiment with proof of concepts, and build out scalable real-time production systems to tackle challenges the company faces. What you'll do: Design, code, test, and debug ML applications and constantly improve large-scale global systems that respond to millions of real-time requests per second efficiently. Prototype solutions, conduct data analyses to tackle large-scale inference problems, and run ML experiments to test new modeling ideas. Write clean, efficient, and maintainable code using industry best practices. Work multi-functionally with other teams to develop standard methodologies in model building and validation, and collaborate closely with engineering teams to deliver high-quality ML products. Identify performance bottlenecks and optimize system components for enhanced scalability. Mentor machine learning engineers to grow their careers and improve their skills, including participating in code reviews and providing constructive feedback to team members. Generate and review proposals for further research and development directions. Keep up to date with developments in machine learning outside the company. Who you are: M.S in Computer Science or related technical field with 5 - 8 years of industry experience or Ph.D. with 5 years, or equivalent practical experience. You must be work-authorized in the United States without the need for current or future employer sponsorship. This is a hybrid role based in our San Francisco office. To ensure a manageable commute for in-office days, candidates must reside within a 60-mile radius of San Francisco, CA. No relocation candidates at this time. Fluency in Python, Java, or similar object-oriented programming language. Proficiency with ML algorithms such as classification, control systems, optimization, clustering, LLMs, or recommendation systems. An interest in distributed system and software design, concurrent algorithms, data structures, and software engineering. Solid foundation in math, statistics, data visualization, and storytelling. Demonstrated analytical, planning, and social skills. Experience coaching and developing junior machine learning engineers. The salary range for this position is $186,900 - $217,200 LI-AC1 At Quantcast, we craft offers that reflect your unique skills, expertise, and geographic location. On top of a competitive salary, this position includes a performance bonus, equity, and a comprehensive benefits package. For more details, visit our Careers Page and see how we support our team. We are headquartered in San Francisco with offices around the world. Quantcast is an Equal Opportunity Employer. Please see the Applicant Privacy Notice for details on our applicant privacy policy. Join the team that unlocks potential.

Keywords: Quantcast, Pittsburg , Sr Machine Learning Engineer, Engineering , San Francisco, California