Machine Learning Scientist - Performance Marketing

Role description

As a Machine Learning Scientist in PPC, your work will focus on devising and implementing advanced machine learning and optimization approaches for the next generation of  performance marketing bidding algorithms. You will optimize our bidding strategy across search platforms, ensuring our competitive edge in the complex dynamics of the bidding marketplace and online auction mechanisms. This role requires a unique combination of deep theoretical knowledge around large‑scale optimization techniques, auction theory, and the application of state‑of‑the‑art machine learning methodologies to scalable industrial setups.

• Develop innovative techniques for the next phase of our online bidding algorithms, including modeling user intent, modeling the online marketplaces, and optimizing our bidding strategy to maximize the efficiency of how we spend our advertising budgets.
• Design and implement scalable evaluation pipelines, including synthetic data generation and benchmarking for model quality, relevance, and consistency.
• Ensure the reliability, efficiency, and scalability of evaluation tools and frameworks in both offline and online environments.
• Conduct in‑depth data analysis to define and track evaluation metrics, validate label quality, and explore performance across different traffic siloes.
• Collaborate closely with ML engineers to integrate evaluation components into production pipelines, supporting continuous improvement of bidding applications.
• Work cross‑functionally with commercial and analytics teams to align evaluation strategies with business goals and user impact.

• Master’s degree or PhD required (Computer Science, Engineering, Mathematics, Artificial Intelligence, Physics)
• Industry or academia knowledge of large scale optimisation techniques or mechanism design or auction theory.
• Experience contributing to innovative machine learning and optimisation solutions for large‑scale business problems, preferably evidenced by peer‑reviewed publication, patents, open‑source code or the like.
• Relevant work or academic experience (MSc + 1 year of working experience), involved in the application of Machine Learning to business problems.
• Knowledge of some machine learning facets: working with large data sets, model development, statistics, experimentation, data visualization, optimisation, software development.
• Understanding of cross‑functional development of machine learning products (e.g., Developers, Commercial, Data Analytics, etc.).
• Working knowledge of Python, SQL/Big Query, Spark.
• Excellent English communication skills, both written and verbal.

• Annual paid time off and generous paid leave scheme including parent, grandparent, bereavement, and care leave.
• Hybrid working including flexible working arrangements and up to 20 days per year working from abroad (home country).
• Industry‑leading product discounts – up to 1400 per year – for yourself, including automatic Genius Level 3 status and  wallet credit.
• Contributing to a high‑scale, complex, world‑renowned product and seeing real‑time impact of your work on millions of travellers worldwide.
• Working in a fast‑paced and performance‑driven culture.
• Opportunity to utilise technical expertise, leadership capabilities and entrepreneurial spirit.
• Promote and drive impactful and innovative engineering solutions.
• Technical, behavioural and interpersonal competence advancement via on‑the‑job opportunities, experimental projects, hackathons, conferences and active community participation.
• Competitive compensation and benefits package.

is proud to be an equal opportunity workplace and is an affirmative action employer. All qualified applicants will receive consideration for employment without regard to race, colour, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. We strive to move well beyond traditional equal opportunity and work to create an environment that allows everyone to thrive.