Staff Machine Learning Engineer - Ads Bidding

About this role

Staff Machine Learning Engineer – Ads Bidding The Team The Ads ML team builds and maintains the machine learning models powering Deliveroo's advertising product — connecting consumers with relevant ads and helping merchants, grocers, and FMCG brands grow through the platform. The UK team is ~11 MLEs across ads and promotions, and collaborates closely with the US team (meetings capped at 4pm UK to protect reasonable hours). The Problem Deliveroo is migrating ads from cost-per-click (CPC) to cost-per-order (CPO) — merchants pay when an ad drives an order, not when it's clicked. This is a genuinely open, cutting-edge problem: very few companies have solved it, and there's no established playbook to follow. The exact approach is under active discussion and you'd be central to driving it. You will: • Own the design and execution of the CPC-to-CPO migration, including the core open question of whether the system stays CPO-facing externally while optimising CPC behind the scenes, or some hybrid of the two • Build and improve the bidding surface: goal-based automated bidding, Target CPO, optimised CPC, and Target ROAS • Own yield management tied to ROS targeting • Partner daily with the DoorDash US team to align on approach across markets • Set technical direction for the domain Requirements • Expertise in ad economics, marketplace bidding, or auction theory • Direct working experience with optimised CPC, target CPO, goal-based automated bidding, and target ROAS • Strong self-driven leadership baseline — you'll be setting direction in an ambiguous space, not executing against an established one • 7+ years writing production code in Python; solid ML fundamentals in ranking, recommendation systems, or bidding/auction systems • A bias for simplicity and a focus on shipping work with measurable business impact • Strong cross-functional communication — you'll be working closely with Product, Commercial, and the wider DoorDash team Why Join Us? At Deliveroo, you'll do work that matters—solving real-world problems in a three-sided marketplace that’s constantly evolving. We’re food lovers, problem solvers, community builders and more, brought together by a shared drive to make things better. Working here you can expect to: 🔧 Solve meaningful problems at real scale Work on a complex, always-on marketplace that impacts millions every day. 🌱 See your impact, fast Ship, test and improve ideas quickly in a low-hierarchy, high-ownership environment. 🧠 Grow through challenge and ownership Take on big, ambiguous problems and accelerate your career with strong support. 🌎 A culture built for builders High standards, collaboration, flexible working and continuous learning. 💰 Share in the success you help create Competitive salary and equity options, so you’re rewarded for the impact you make. ➡️ Want a deeper look at how we build? Check out our Tech Blog. Our Global Structure Deliveroo is now part of DoorDash, bringing together teams with even greater reach, scale, and ambition. Depending on your role, you may collaborate with teammates, systems, and leaders across DoorDash and Wolt. Together, we’re unlocking new possibilities as one global team. Diversity, Equity and Inclusion At Deliveroo, we know that a great workplace reflects the world around us and that true diversity and inclusion make us stronger, more creative, and better at what we do. We’re committed to fostering an environment where everyone can do their best work and feel they belong. We believe in equality of opportunity and welcome candidates from all backgrounds regardless of age, gender, ethnicity, disability, sexual orientation, gender identity, socio-economic background, religion, or belief. If you have a disability or long-term health condition and need support to apply for one of our roles, or require any reasonable adjustments during the recruitment process, you’ll have the opportunity to let us know once you’ve submitted your application. We’ll share details on how to request support so we can ensure you have a fair and equitable experience. If you’re excited about making a real impact in a fast-moving marketplace and growing your career alongside ambitious, supportive teams, we’d love to hear from you!