Senior Machine Learning Engineer I - GenAI Applications Teams

About Us

At Booking.com, data drives our decisions. Technology is at our core. And innovation is everywhere. But our company is more than datasets, lines of code or A/B tests. We're the thrill of the first night in a new place. The excitement of the next morning. The friends you encounter. The journeys you take. The sights you see. And the memories you make. Through our products, partners and people, we make it easier for everyone to experience the world.

About the Team

This opening is for the GenAI Applications Teams within the Data & AI Marketplace department.

The GenAI Applications teams are responsible for designing and delivering agentic, ML-powered solutions for some of our most impactful products, including booking search experiences, trip planning, and customer service. The teams build AI-driven applications and conversational agents, such as chatbots and intelligent assistants that significantly enhance the end-to-end customer experience.

Role Description

As a Senior Machine Learning Engineer, you will work closely with top notch engineers and data scientists to design, develop, evaluate and deploy Gen AI-powered solutions for scalable, customer-facing applications. Your work will focus on building and applying state-of-the-art agentic capabilities to drive business impact and improve efficiency.

Key Responsibilities

• Design, develop, and deploy high-quality, performant, and efficient Generative AI-powered solutions and agentic systems into production environments.
• Evaluate and define optimal architectural solutions by considering emerging technologies, business needs, and technical requirements for latency, throughput, and scale.
• Own services end-to-end, including implementing robust monitoring and maintenance strategies to ensure application and ML health, quality, and performance.
• Write and maintain clean, scalable, and well-tested production code, ensuring reproducibility and seamless integration via CI/CD pipelines.
• Pioneer and promote best practices and the adoption of cutting-edge technology in GenAI application development.
• Collaborate effectively with Product Managers, Data Scientists, and Analysts to understand business requirements and translate them into technical ML and agentic solutions.
• Provide technical guidance and mentorship to other engineers, contributing to the team's overall technical development.

Required Qualifications & Skills

• Bachelor's or master's degree in Computer Science, Engineering, Statistics, or a related field.
• Minimum of 6 years of experience as a Machine Learning Engineer or a similar role, with a consistent record of successfully delivering ML solutions to production.
• Experience of working on products that impact a large customer base.
• Demonstrable experience and capabilities with Generative AI applications, including Large Language Models (LLMs), Agentic Systems, and MCP in production environments.
• Deep understanding of core machine learning algorithms, statistical models, evaluation methods, and data structures.
• Experience in designing, building, and deploying models using cloud frameworks (e.g., AWS Sagemaker) and standard ML libraries (e.g., TensorFlow, PyTorch, or scikit-learn).
• Strong programming proficiency in languages such as Python and Java.
• Strong coding practices, including writing and reviewing production-quality, maintainable, and well-tested code, with the ability to effectively leverage modern AI coding assistants while maintaining high standards for correctness, readability, and system design.
• Experience with big data processing frameworks (e.g., Pyspark, Apache Flink, Snowflake) and demonstrable experience with relational/NoSQL database systems (e.g., MySQL, Cassandra, DynamoDB).
• Excellent English communication and presentation skills, both written and verbal.

Preferred Qualifications

• Experience deploying large-scale language models (e.g., GPT, BERT, or similar architectures).
• Proficiency in data manipulation, analysis, and visualization using tools like NumPy, pandas, and matplotlib.
• Experience with experimental design, A/B testing, and evaluation metrics for ML models.

Benefits & Perks

• 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 Booking.com wallet credit

Diversity, Equity and Inclusion

Diversity, Equity & Inclusion have been a core part of our company culture since day one. This ongoing journey starts with our very own employees, who represent over 140 nationalities and a wide range of ethnic and social backgrounds, genders and sexual orientations.

At Booking.com, the diversity of our people doesn't just build an outstanding workplace, it also creates a better and more inclusive travel experience for everyone. Inclusion is at the heart of everything we do. It's a place where you can make your mark and have a real impact in travel and tech.

We ensure that colleagues with disabilities are provided the adjustments and tools they need to participate in the job application and interview process, to perform crucial job functions, and to receive other benefits and privileges of employment.

Application & Hiring Process

This role does not come with relocation assistance.

Booking.com 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, color, 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.

Pre-Employment Screening

If your application is successful, your personal data may be used for a pre-employment screening check by a third party as permitted by applicable law. Depending on the vacancy and applicable law, a pre-employment screening may include employment history, education and other information (such as media information) that may be necessary for determining your qualifications and suitability for the position.