Principal Machine Learning Engineer (Search Platform)

Principal Machine Learning Engineer (Search Platform)

OLX Group

Remote, Portugal

As the Principal Search Machine Learning Engineer, you’ll be the technical guiding force behind this transformation. You’ll work alongside our Principal Search Engineer to shape the architecture, mentor the team, and deliver solutions that bring measurable business and user impact. You’ll have full ownership to explore, experiment, and push boundaries - from prototyping new search models to deploying them at scale.

What you will be doing:

• Shape the future of AI-powered search across all OLX verticals. You’ll drive the technical vision, guide a multidisciplinary team, and ensure our Search AI Platform becomes a foundation for scalable, intelligent discovery experiences for millions of users.
• Lead the design and evolution of OLX’s Search AI Platform, developing LLM- and GenAI-based systems that power discovery and relevance across Motors, Real Estate, Jobs, and Goods.
• Partner with the Principal Search Engineer to define and implement a unified technical strategy for search, ranking, and retrieval at scale.
• Guide a cross-functional team of ML engineers, data scientists, and platform engineers, fostering technical excellence, experimentation, and rapid iteration.
• Prototype, evaluate, and productionize new ML models, including embedding-based retrieval, personalization, and relevance optimization.
• Collaborate with product and analytics teams to define success metrics, integrate with A/B testing pipelines, and measure real customer impact.
• Mentor and inspire data scientists and ML engineers across OLX’s global hubs, sharing best practices and shaping the future of applied ML at scale.
• Stay hands-on, driving implementation in Python and AWS while exploring state-of-the-art advances in LLMs, GenAI, and search infrastructure.
• Promote a culture of learning and innovation, helping the team iterate fast, fail fast, and learn continuously.

What are we looking for:

• Based in Portugal, with the ability to collaborate across global teams.
• Strategic and hands-on technical leader who thrives at the intersection of machine learning, large-scale systems, and product impact.
• Deep expertise in search and relevance, including ranking models, retrieval systems, and modern representation learning (e.g., embeddings, transformers).
• Proven experience designing and productionizing ML solutions at scale in real-world environments.
• Strong background in Generative AI and LLMs, with an understanding of their application to search and content understanding.
• Ability to inspire and lead cross-functional initiatives, aligning multiple teams toward shared technical outcomes.
• Proficient in Python and familiar with at least one other programming language (e.g., Kotlin, Java); experienced with ML frameworks such as TensorFlow or PyTorch.
• Solid understanding of data pipelines, experimentation frameworks, and distributed systems in cloud environments (preferably AWS).
• Exceptional analytical, communication, and stakeholder management skills, capable of translating complex ideas into actionable solutions.
• Passion for building systems that connect millions of users to what matters most, through better search, relevance, and personalization.

Nice to have:

• Experience with cloud-based tools for production use (e.g., AWS Athena, AWS Sagemaker, AWS Spectrum, AWS Kinesis) or equivalent.
• Experience building large-scale batch and real-time data pipelines with open source data processing frameworks like Spark.
• Experience with platforms for programmatically authoring, scheduling and monitoring workflows (e.g. Apache Airflow).
• Experience driving initiatives such as Tech Radar for Data Science and interacting with external groups (e.g. Amazon ML Solutions Lab or similar) to formulate and progress the Data Science Tech agenda.