Applied Scientist

About Wolt

At Wolt, we create technology that brings joy, simplicity and earnings to the neighborhoods of the world. In 2014 we started with delivery of restaurant food. Now we’re building the delivery of (almost) everything and you’ll find us in over 500 cities in 30 countries around the world. In 2022 we joined forces with DoorDash and together we keep on dreaming big and expanding across the globe.

Wolt’s AdTech & Promotions team is building the machine learning and optimization systems that power advertising and promotions across our marketplace. Our work spans conversion modeling, retrieval, auction, campaign optimization, forecasting, measurement, and advertiser-facing tooling — all with the goal of helping merchants and brands grow while keeping the experience relevant for consumers. As we expand our offering, we are investing in new capabilities that combine real-time data, scalable systems, and intuitive user experiences to unlock the next phase of growth.

We’re looking for an Applied Scientist to join the Wolt AdTech & Promotions team, who can help us build impactful, reliable, and scalable ML systems that directly impact revenue and advertiser success.

What you’ll be doing

• As part of the AdTech Experience team you will be designing and implementing large-scale machine learning and optimization solutions that power Wolt’s ads experience.
• You will work closely with fellow engineers, product managers, designers, and data scientists in executing these projects, but also help to shape the vision and the roadmap for the team leveraging ML.
• As a senior team member, you will provide technical leadership to the team, participate in hiring, and provide mentorship for junior team members alongside contributing to the wider applied science community.

As a Senior Applied Scientist in the AdTech Experience team, you will:

• Design, build, and productionize ML and optimization systems for Wolt’s ads products, including areas such as ranking, targeting, campaign optimization, forecasting, and measurement.
• Translate ambiguous business and marketplace problems into clear scientific problem formulations, success metrics, experiments, and production-ready solutions.
• Partner closely with engineering, product, design, analytics, and business teams to shape the ads roadmap and ensure science work translates into measurable advertiser and marketplace impact.
• Improve the quality, relevance, efficiency, and commercial performance of ads across Wolt’s consumer and merchant experiences.
• Provide technical leadership across the team by mentoring others, reviewing scientific and technical designs, raising the bar for experimentation, and contributing to hiring.
• Contribute to the broader applied science community at Wolt by sharing methods, reusable patterns, and learnings from ads problems.

Our humble expectations

We’re looking for an Applied Science enthusiast who is passionate about using machine learning and AI to make a measurable impact. Here’s what we hope you bring:

• Experience in Ads/RecSys/Search: Significant experience building and productionizing machine learning, ranking, recommendation, search, or optimization systems in high-scale consumer or marketplace environments.
• Passion for Applied Science and Machine Learning: You identify as a problem solver who loves leveraging data science, machine learning and AI to drive business results and create real-world impact.
• Expertise in Production-Grade ML Solutions: You know what it takes to build robust, scalable models suitable for large-scale deployments. You’re comfortable managing the entire lifecycle of ML projects, from ideation through to production and ongoing maintenance.
• Strong Foundations in ML and Statistics: You bring a solid educational background and practical skills in modeling and statistics, enabling you to design reliable and meaningful solutions.
• Engineering Excellence: You’re skilled in writing production-level Python code and following engineering best practices, ensuring your solutions are efficient, maintainable, and scalable. You have both read and written some SQL in your time and don’t find it scary. You have the ability (or willingness to learn how) to productionalize ML solutions with our ML tooling.
• Excellent Communication and Stakeholder Management Skills: You can effectively communicate complex technical concepts to non-technical audiences, bridging the gap between applied science and business needs in a global organization.
• Analytical Problem-Solving: You excel at breaking down complex business challenges into clear, solvable machine learning problems, and designing data-driven solutions to address them. You understand that model metrics are most valuable when they are connected to business outcomes.
• Understanding of Experimental Design: You have a good grasp of experimental methodologies and analysis, allowing you to support experimentation and validation of the impact of your work.
• Curiosity and practical enthusiasm for using modern AI tools and agents in your daily work!

What we offer

At Wolt, this role provides a great opportunity to work on challenging AdTech problems at scale, where technical decisions directly impact revenue and user experience. You will play a key role in building and evolving the next generation of advertisement tools and platforms, shaping how advertisers create, manage, and optimize campaigns across Wolt. This is not just about maintaining systems, but about defining and scaling new capabilities in a fast-growing domain.

Our compensation follows a total compensation model, combining a competitive base salary with DoorDash RSUs. You’ll be part of a global company operating at scale, collaborating with teams across Europe and the US, and solving problems that span multiple markets, use cases, and customer segments. Alongside the technical challenge, you’ll work with talented engineers and leaders in a diverse and international environment, shaping both our systems and engineering culture while mentoring and learning from others.