Hiring: Principal Machine Learning Engineer, Ads & Promos Delivery Company: DoorDash Location: Sunnyvale, CA Job Posted Time: 2026-09-16 10:07:13 Target Skills & Keywords : A/B Testing, Deep Learning, LLM, NLP, TestNG, jQuery About the job Experience: •5+ years of experience building, deploying, and scaling ML and AI models for large-scale, user-facing or data-intensive products. Required Skills: •Rigorously evaluate ML and LLM models using a combination of offline analysis and online experimentation, designing metrics and experiments that clearly measure quality, impact, and tradeoffs. •Own the full model lifecycle from research to production, including data analysis, model development, evaluation, offline and online A/B testing, and continuous iteration. •Partner closely with product managers, data scientists, and designers to ensure AI-driven systems deliver meaningful, user-facing improvements. •Stay at the forefront of ML and AI innovation by assessing emerging research and translating promising approaches into scalable, production-ready systems. •This is a high-impact role for someone who enjoys combining economic intuition, large-scale ML modeling, and applied engineering to solve complex real-world optimization problems. •You’re Excited About This Opportunity Because You Will… •Own impactful ML systems: Build and improve models that directly have a large impact on top and bottom line financials. •Collaborate cross-functionally: Partner with engineering, analytics, product, and operations to iterate quickly, moving models from prototype to production •Shape the future: We're one of the fastest growing Ads platforms in the world and we're looking to take that even further! •We’re Excited About You Because You Have… •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 (e.g., Claude Code, Codex, Cursor) in the full software development lifecycle, including designing, generating code, testing, monitoring and releasing software •BS, MS, or PhD in Computer Science, Engineering, or a related field, or equivalent practical experience. •Deep expertise in one or more of the following areas: deep learning, large language models, information retrieval, ranking and relevance, recommendation systems, natural language processing, or content Interested candidates, please apply directly through the job posting on company's career page or try via AI auto apply on this platform. Don't miss this opportunity to join a forward-thinking team!