Senior Machine Learning Engineer, Search

Job Description:

About the Team:

Our Technology team drives the evolution of our Engineering, Data, Product and User Experience functions. With a keen focus on delivering cutting-edge solutions, we shape the digital landscape for our customers, readers and users. From revolutionizing visuals to optimizing tools and harnessing the power of data, mobile, video and social platforms, our team is committed to providing a seamless and immersive experience across all touchpoints. Collaborating closely with our newsrooms and strategic partners, we spearhead the development of groundbreaking products and technologies.

We are looking for a Senior Machine Learning Engineer to join our Search team in Barcelona. You will design and build systems that deliver highly relevant, personalized experiences across our digital products. This role sits at the intersection of backend engineering, data, and applied AI—leveraging modern architectures and machine learning techniques to connect users with the most relevant content.

You will play a key role in building scalable search indexing, retrieval and ranking systems that serve content to millions of readers in real time. You will partner closely with product, data science, and engineering teams, bringing technical depth and sound judgment to architectural decisions, model design, and evaluation methodology.

• Design, build, and operate search systems and services powering content discovery and user engagement.

• Develop and improve ML models across the whole personalization stack, from candidate generation to final ranking.

• Use data-driven methods to improve candidate retrieval, leveraging embeddings, two-tower architectures, and user/content signals.

• Drive experimentation and A/B testing to measure impact and iterate on models and features.

• Leverage LLMs to enhance content understanding and feature extraction.

• Optimize systems for performance, latency, and scalability across high-traffic environments.

• Contribute to engineering best practices, including testing, observability, and CI/CD.

• Collaborate with product managers, data scientists, and analysts to translate business needs into scalable technical solutions.

• 2-4 years of industry experience applying machine learning methods, with a strong focus on recommender systems, search, ranking, or personalization.

• Strong proficiency in Python for production ML systems.

• Experience with A/B testing and experimentation frameworks to measure model impact.

• Familiarity with cloud platforms (AWS, GCP, or Azure) and containerized environments.

• Familiarity with SQL and NoSQL databases.

• Degree in computer science, machine learning, statistics, or equivalent work experience.