The Principal Engineer role in the Ads & Promos Delivery team focuses on leading the technical direction for AI-first experiences in ad ranking and relevance systems. This position involves designing and building advanced AI-driven ranking systems that enhance how ads are selected and personalized in real time. The role requires collaboration across teams to ensure the delivery of impactful AI systems while maintaining strict performance standards. As DoorDash expands into new markets, this position offers a unique opportunity to influence the future of ad relevance in a dynamic marketplace.

• 5+ years of experience building, deploying, and scaling ML and AI models for large-scale, user-facing or data-intensive products.
• Proficiency in using AI coding tools in the full software development lifecycle.
• BS, MS, or PhD in Computer Science, Engineering, or a related field, or equivalent practical experience.
• Deep expertise in areas such as deep learning, large language models, information retrieval, ranking and relevance, recommendation systems, or natural language processing.
• Strong programming skills in Python, Java, or C++, with hands-on experience using ML frameworks such as PyTorch, TensorFlow, or XGBoost.
• Extensive experience across the full ML lifecycle, including data analysis, feature engineering, and model evaluation.

• Apply state-of-the-art machine learning and LLM techniques to various problems.
• Evaluate ML and LLM models using offline analysis and online experimentation.
• Own the full model lifecycle from research to production, including data analysis and continuous iteration.
• Collaborate closely with product managers, data scientists, and designers to ensure meaningful improvements.
• Stay updated on ML and AI innovations and translate research into scalable systems.