Senior Principal Applied Scientist

The Size and Fit team is tackling one of the key challenges in the fashion industry: helping online customers confidently find what they love and decide on the right size and fit of clothes and shoes they buy. By doing so, we directly improve customer satisfaction, reduce returns, and drive sustainable, profitable growth. As an interdisciplinary team of applied scientists, software engineers, product managers, and design experts, we work holistically to deliver high-impact solutions with a focus on immediate, scalable results.

While developing and maintaining proven, highly-adopted solutions such as ML-based size recommendations, we push the boundaries of what’s possible in online fashion by rapidly iterating our approaches with cutting-edge AI, including diffusion models, image and video generation, and 3D try-on experiences, to shape the future of Size & Fit.

As a Sr. Principal Applied Scientist on the Size & Fit team, you’ll leverage your deep scientific expertise and leadership to tackle these challenges. You will use our unique, large-scale datasets to drive bold, hands-on research and develop game-changing, production-scale solutions for over 50 million customers. You will apply cutting-edge GenAI and Computer Vision models to help customers express their unique fit preferences, act as a key advisor on our scientific roadmap, and mentor other scientists to deliver innovative, business-oriented outcomes.

Lead & Empower:
Raise the scientific bar—specifically in Computer Vision and Machine Learning—by fostering a culture of rigorous peer review and knowledge sharing. Collaborative Strategy:
Partner with Product Management and Design to refine requirements for initiatives that delight customers. You will translate ambiguous business goals into technical solutions, MVPs, and iterative roadmaps. Research & Innovation:
Stay at the forefront of Computer Vision techniques (GAN’s, Diffusion Models, etc.) and AI/ML. Interest in Data Engineering and ML Engineering is a plus. You will encourage your team to engage with the global research community through publications in prestigious conferences. Operational Excellence:
Act as an advisor by implementing durable, repeatable processes that promote agility. Ensure the systems your team builds and maintains adhere to high standards of MLOps and technical reliability. Mentorship & Growth:
Support the professional development of both junior and senior team members. You will provide constructive, "egoless" feedback, handle performance management, and coach your colleagues to become world-class researchers and engineers.

• Academic Foundation:
  You hold a Ph.D. in Computer Science, Machine Learning, Computer Vision, AI, or a closely related field, paired with 5+ years of post-doctoral industry or academic experience.
• Full-Lifecycle Ownership:
  You possess an extensive track record of driving large-scale ML applications through the complete product lifecycle—from initial problem analysis and data processing to literature review, production deployment, monitoring, and long-term maintenance.
• Technical Mastery:
  You maintain deep hands-on expertise in AI/ML model building & deployment, with proficiency in Python, PyTorch, and modern machine learning frameworks; you excel at rapidly prototyping, iterating on, and deploying hands-on scientific solutions that turn complex business challenges into immediate, scalable wins.
• Specialized Domain Depth:
  You bring in-depth experience in 3D Computer Vision (leveraging GenAI, diffusion models, NeRFs, Gaussian splatting, and 3D reconstruction) and/or scaled application of modern AI/ML techniques built to solve high-impact business problems.
• Exceptional Communication:
  You are fluent…