Senior Machine Learning Scientist

As a Senior ML Scientist at Wayfair, you'll shape the future of how millions of customers are engaged through intelligent, timely, and personalised communication powered by scalable AI systems.

We are looking for an experienced ML scientist to lead the research and development of ML systems that power Wayfair's customer engagement and notification platforms. This includes send decisioning, cross-channel optimisation, and personalised content selection. In this role, you will be responsible for building the next generation of Wayfair's ML stack for notifications, including systems that determine which customers to contact, when to contact them, through which channel, and with what content. You will collaborate closely with engineering, analytics, and product partners within CT to define technical direction and deliver scalable, high-impact solutions. This role is a key contributor within the CT Science organisation, with visibility across marketing, product, and platform teams.

Responsibilities:

• Drive the development of ML systems for notification send decisioning, including ranking and personalisation components.
• Build and improve systems that optimise cross-channel customer engagement (Email, Push, SMS), balancing revenue, engagement, and customer fatigue.
• Develop multi-objective optimisation frameworks to drive long-term customer value while minimising unsubscribe and disengagement risk.
• Continually improve the team's ability to build efficient and scalable ML models by leveraging industry best practices and maintaining high standards of model quality and robustness.
• Collaborate closely with product and engineering partners to build and evolve Wayfair's next-generation notification and customer engagement stack.
• Design and iterate on decisioning systems under competing objectives using experimentation and data-driven optimisation.
• Contribute as a senior individual contributor within the CT Science group and the broader ML community at Wayfair.
• Maintain a strong customer-centric perspective in how problems are framed and solved.

Requirements:

• Bachelor's or Master's degree in Computer Science, Mathematics, Statistics or a related field.
• 10+ years of experience in building large-scale ML algorithms.
• 4+ years of demonstrated experience owning and delivering end-to-end ML systems or providing technical leadership on complex ML problems.
• Strong theoretical understanding and practical experience applying statistical models (e. g., regression, clustering) and ML algorithms (e. g., decision trees, neural networks, transformers, NLP techniques) at scale.
• Experience working on ranking, recommendation, ads, or notification systems.
• Proficiency in programming languages such as Python or R, and ML libraries such as TensorFlow or PyTorch, to develop production-grade systems.
• Ability to partner cross-functionally to own and shape technical roadmaps.
• Intellectual curiosity and a strong desire to continuously learn!

Nice to Have:

• PhD in Computer Science, Mathematics, Statistics or related field.
• Experience with marketing technology, customer engagement platforms, or send optimisation systems.
• Familiarity with multi-objective optimisation, causal inference, or experimentation frameworks.
• Familiarity with Generative AI and its applications in personalisation or content generation.
• Experience with cloud platforms (GCP, AWS, Azure) and ML orchestration tools (Airflow, Kubeflow, MLflow).