Principal Machine Learning Engineer, Ads Delivery

About Pinterest: Millions of people around the world come to our platform to find creative ideas, dream about new possibilities and plan for memories that will last a lifetime. At Pinterest, we’re on a mission to bring everyone the inspiration to create a life they love, and that starts with the people behind the product. Discover a career where you ignite innovation for millions, transform passion into growth opportunities, celebrate each other’s unique experiences and embrace the flexibility to do your best work. Creating a career you love? It’s Possible. At Pinterest, AI isn't just a feature, it's a powerful partner that augments our creativity and amplifies our impact, and we’re looking for candidates who are excited to be a part of that. To get a complete picture of your experience and abilities, we’ll explore your foundational skills and how you collaborate with AI. Through our interview process, what matters most is that you can always explain your approach, showing us not just what you know, but how you think. You can read more about our AI interview philosophy and how we use AI in our recruiting process here . Within the Ads Delivery team, we try to connect the dots between the aspirations of pinners and the products offered by our partners. In this role, you will be responsible for developing and executing a vision for the evolution of the Pinterest marketplace. You will design and implement systems that improve the ads delivery funnel, experiments that shape the utility function, auction mechanism design, ad allocation and for deriving new insights through analysis of the marketplace dynamics. In short, this is a unique position, where you’ll get the freedom to work to bring together pinners and partners in this unique marketplace. What you’ll do: Build and improve backend systems and statistical models that underlay the marketplace to maximize value for Pinners, Partners and Pinterest. Define and implement experiments to understand long term Marketplace effects. Develop strategies to balance long and short term business objectives. Drive multi-functional collaboration with peers and partners across the company to improve knowledge of marketplace design and operations. What we’re looking for: Degree in Computer Science, Machine Learning, Statistics or related field. 10+ years of professional experience as a hands-on engineer and technical leader leading multiple projects. Strong software engineering and mathematical skills with knowledge of statistical methods. Hands-on experience with large-scale online e-commerce systems is a plus. Background in computational advertising is preferred. Nice to Have : Experience using Cursor, Copilot, Codex, or similar AI coding assistants for development, debugging, testing, and refactoring Familiarity with LLM-powered productivity tools for documentation search, experiment analysis, SQL/data exploration, and engineering workflow acceleration In-Office Requirement Statement: We let the type of work you do guide the collaboration style. That means we're not always working in an office, but we continue to gather for key moments of collaboration and connection. This role will need to be in the office for in-person collaboration 1-2 times/month , and therefore needs to be in a commutable distance from one of the following offices: San Francisco, Palo Alto, Seattle. Relocation Statement: This position is not eligible for relocation assistance. Visit our PinFlex page to learn more about our working model. #LI-HYBRID #LI-SM4 At Pinterest we believe the workplace should be equitable, inclusive, and inspiring for every employee. In an effort to provide greater transparency, we are sharing the base salary range for this position. The position is also eligible for equity. Final salary is based on a number of factors including location, travel, relevant prior experience, or particular skills and expertise. Information regarding the culture at Pinterest and benefits available for this position