Data Scientist – RecSys Remote, Portugal | Product DepartmentAbout the roleOur client - they're looking for a Data Scientist specialising in Recommendation Systems to join their global Data Science team — building large-scale, production-grade RecSys that impact millions of players worldwide, working alongside Data Scientists, Engineers and Data Engineers.Key ResponsibilitiesDesign, implement and optimise end-to-end recommendation pipelines (data ingestion to model inference)Build and maintain scalable ETL pipelinesDevelop, evaluate and continuously improve ML models for RecSysResearch and prototype SOTA approaches to improve recommendation qualityIntegrate multi-modal data (behavioural, transactional, contextual) into modelsDesign and analyse A/B tests; build dashboards to track model metrics and business KPIsCollaborate with Data Engineers, Software Engineers and stakeholdersRequired SkillsStrong Python (production), including Pandas, Polars, NumPy, scikit-learn, PyTorch, TensorFlow, JAX, Hugging FaceEnd-to-end ML deployment on cloud platforms (Azure, GCP or AWS) — ETL to monitoringDeep learning–based recommender systems (next-item prediction, sequential models)SQL and NoSQL databases (PostgreSQL, Redshift, Snowflake, BigQuery, MongoDB, Cassandra)Unit/integration testing (Pytest), CI/CD, DockerBonus Points ForLarge-scale RecSys (candidate generation, ranking, retrieval, personalisation)Publications in deep learning at relevant conferencesTransformer-based models / LLMs applied to RecSysDistributed training and big data tech (Spark, Kafka, Databricks)Multi-modal models (text, images, audio)What They OfferCompetitive comp based on experienceRemote-friendly, flexible hoursWork on state-of-the-art ML infrastructure at scaleOpen-source contribution opportunities