At The Trade Desk, we design powerful, enterprise-grade tools that help the world’s top advertisers make smarter decisions and achieve better results. As a Principal Designer, you’ll play a key role in elevating the quality and consistency of design across our product suite. You’ll drive end-to-end design for foundational areas of Kokai, our next-generation platform — shaping not only the UX direction, but also how we define and solve complex problems. In this role, you’ll help unify the platform, reduce fragmentation, and bring coherence to the user experience by identifying shared patterns, closing quality gaps, and aligning teams on best practices. You’ll work closely with leaders in Product, Engineering, and Research while operating at the highest level of individual contribution — crafting experiences that empower users to move faster, focus on what matters, and make smarter decisions with confidence. Your leadership will help foster a culture of excellence where design quality is everyone’s responsibility and a core driver of product success. We’re looking for a thoughtful, systems-minded designer who thrives in complexity, cares deeply about craft, and inspires others through influence and example.