Staff Machine Learning Engineer, Growth Activation

Join Pinterest’s Growth Activation team as a Staff Machine Learning Engineer and own the most critical moments of the user journey—from sign-up to that first unforgettable “aha.” You’ll design and deploy ML-powered experiences that turn curiosity into long-term engagement, moving the needle on activation, retention, and top-line growth. If you love digging into data, collaborating across core ML and product teams, and shipping experiments that directly shape Pinterest’s future, this is where you’ll make your impact.

As the ML Lead for the Activation team, you'll drive the technical strategy and execution for solving recommendation challenges for Pinterest's new and returning users. This is a high-impact role focused on understanding what drives user activation, identifying the right ML problems to solve and moving quickly through experimentation to drive measurable results.

What You'll Do:

• Lead the technical roadmap for activation ML, developing expertise in cold start challenges for users with limited interaction history and defining the highest-impact opportunities to pursue
• Drive hands-on ML work including building models from scratch, feature engineering and rapid experimentation to understand what drives activation for new and returning users
• Partner with other ML teams (homefeed, notifications, search, User Understanding, ML Infra) to influence their roadmaps, ensure new and returning user needs are prioritized and identify where activation should build specialized capabilities
• Work closely with product managers and data scientists to translate user problems into ML opportunities, scope ambiguous challenges and make pragmatic trade-offs between technical sophistication and business impact
• Run experiments to improve how we capture and leverage user intent signals from entry points, optimize initial content recommendations and test new approaches to activation
• Own technical strategy for key activation initiatives, making decisions about what to build, when to partner with other teams and how to maximize impact with a lean team
• Mentor and develop the ML team, establishing best practices for tackling new and returning user challenges and scaling impact over time
• Drive measurable improvements in user activation and retention metrics through thoughtful problem selection, rapid iteration and data-driven decision making

What we're looking for

• 6+ years of experience building and shipping ML models, with focus on recommendation systems, ranking, personalization or growth challenges
• 2+ years of experience as a technical lead or senior IC, driving technical strategy and leading ML projects with measurable business impact
• Strong product mindset and ability to identify which ML problems to solve for maximum business impact, not just implement predetermined problems and solutions
• Track record of moving fast through experimentation, iterating based on results and driving projects to completion in ambiguous environments
• Experience with cold start challenges or working with users with limited interaction history, including techniques for personalization with limited user data
• Strong collaboration skills including partnering with product teams, influencing roadmaps, working across teams and driving alignment on technical approach
• Experience mentoring ML engineers and establishing technical best practices for a team
• Degree in Computer Science, Machine Learning, Statistics or a related field, or equivalent experience

Relocation Statement:

• This position is not eligible for relocation assistance. Visit our PinFlex page to learn more about our working model.

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 time/quarter and therefore can be situated anywhere in the province of Ontario or British Columbia. This position is not eligible for relocation assistance. Visit our PinFlex page to learn more about our working model.

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