Senior Applied Scientist

The Trade Desk is a global technology company and the world’s leading independent platform for digital advertising, with nearly 4,000 employees across more than 30 offices. Our technology helps advertisers reach the right audiences across the open internet — from streaming TV and podcasts to mobile apps, news, and more.

Advertising powers the content people love. By making it more transparent, effective, and responsible, we help support trusted journalism, quality entertainment, and creators worldwide. The world’s brands and agencies rely on us to reach their customers and grow their businesses responsibly.

The scale of our platform brings unique technical challenges — from processing massive datasets in real time to building systems that operate reliably on a global scale. When you work here, your impact is worldwide. We welcome diverse perspectives, encourage curiosity, and build teams that learn from one another. If you’re driven to solve meaningful challenges, we’d love to meet you.

What we do:

Applied scientists at TTD work closely with engineering throughout the lifecycle of the product, from ideation to production and monitoring. Our applied scientists are end-to-end owners. You will participate actively in all aspects of designing, researching, building, and delivering data-focused products for our clients and traders.

With this role in AI Lab, you will focus on designing and developing agentic AI applications and systems, such as The Trade Desk's AI Assistant. You will own a technical area end-to-end, from evaluation through production, while also raising the bar for the scientists and engineers around you.

What you'll do:

• Drive the evaluation platform for the AI Assistant, including benchmark generation, human and AI-judge scoring, and scenario-driven testing aligned with human feedback.

• Drive prompt and harness optimization, including automatic tuning and research, and own the release gate that decides what ships to traders and buyers.

• Build and maintain the guardrail and safety framework for input and output checks across all agents in the AI Assistant.

• Set the evaluation, best practices and training standards that other teams adopt as agentic AI spreads across the business.

• Mentor the scientists and engineers around you, and contribute to the applied science roadmap for AI Lab, identifying high-impact problems and coordinating with engineering, AI Infrastructure, and Omnichannel opportunities.

Who you are:

• You have a sustained track record of turning research into agent capabilities that ship, and you think beyond the immediate task to understand why it matters.
• You are a driver. You can scope a six-week delivery cycle (our current shipping cadence, matching the wider product organization), keep it moving, and know when shipping fast would compromise the quality of what goes out.
• You have a strong sense of data and model intuition. At our scale, and in a fast-moving agentic space, off-the-shelf approaches often do not hold up, so you can work from first principles to build evaluation, guardrails, and optimization that fit our systems.
• You have a product-focused and start-up mindset and enjoy moving quickly on innovative product ideas, not just the technical problems underneath them.
• You mentor by doing. You guide and teach, bringing others along with you.
• You have a habit of guiding AI-assiste