Machine Learning Scientist III

About the role

Expedia Group’s Advertising Machine Learning team is looking for a Machine Learning Scientist III to design and deliver predictive models that power real‑time ad auctions and personalised traveller experiences. You will work across both auction and personalisation systems, influencing marketplace performance at scale.

Key responsibilities

• Design, develop and apply ML, statistical and optimisation models for click‑through rate, booking propensity and advertiser bidding dynamics.
• Translate ambiguous business questions into measurable scientific problems, define success metrics and drive data‑driven recommendations.
• Partner with engineers, product managers and analysts to productionise models and integrate them into large‑scale distributed systems.
• Build scalable solutions covering feature engineering, experimentation design (A/B testing), data modelling and model monitoring.
• Safely integrate modern ML techniques, including selective use of GenAI/agentic AI, to enhance modelling and system capabilities.

Required profile

• Advanced degree (MS or PhD) in Machine Learning, Computer Science, Statistics, Applied Mathematics, Economics or related field.
• 5+ years of industry experience applying ML, statistical modelling, experimentation or optimisation in production environments.
• Proven ownership of end‑to‑end ML solutions with accountability for model quality, business impact and reliability.
• Strong problem‑solving skills, ability to communicate complex technical concepts and collaborate cross‑functionally.

Required skills

• Python programming and its ML/data ecosystem (e.g., PySpark, pandas, TensorFlow, PyTorch).
• SQL for large‑scale data querying.
• Experience with A/B testing, feature engineering and production ML pipelines.