Senior Data Scientist

We are a team of tech and data enthusiasts on a mission to bring together the best minds in IT and analytics. Our goal? To build cutting-edge analytical hubs that empower our partners to become truly data-driven organizations.We are currently looking for a Senior Data Scientist to lead the design, development, and deployment of advanced analytical solutions within the Global Analytics Unit — a centralized, global team driving smart data products across all business areas.This is a high-impact role for someone who thrives on end-to-end ownership: from exploratory data analysis and model design, through refactoring and stability testing, to production deployment and performance monitoring.Why join usIf you’re looking for an opportunity to:Tackle complex, real-world business challenges using advanced analytics and machine learningBuild and deploy production-grade models that shape decisions across global marketsWork with an exceptional international team of Data Scientists, ML Engineers, and Data EngineersInfluence architectural and methodological decisions in a rapidly growing global analytics organizationOperate in an environment that values autonomy, innovation, and technical excellence…this might be the perfect fit for you.You’ll also enjoy:Flexible working hours and remote/hybrid work modelPrivate medical care and Multisport cardAccess to online learning platforms, certifications, and global knowledge exchangeA relaxed, non-corporate atmosphere with genuine respect for expertise and ownershipA modern office in central Warsaw with great transport linksYour roleAs a Senior Data Scientist, you will take ownership of developing and productionizing advanced data science models and services. Your work will go far beyond notebooks — you’ll help design stable, reproducible, and automated ML pipelines.You will:Lead end-to-end data science projects, from problem framing and data exploration to deployment and monitoringDevelop, refactor, and productionize robust data preprocessing pipelines for increased stability and scalabilityBuild and maintain reusable helper functions for hyperparameter optimization, feature selection, and model evaluationImprove model accuracy and diagnostics using weighted R², adjusted R², Xi correlation, RMSE, and MAE metricsDesign and implement comprehensive model stability testing frameworks, including:Automate baseline validation and implement standardized approaches to benchmark model performanceWork closely with Data Engineers and MLOps Specialists to deploy models into production using Azure-based infrastructureRefactor and optimize data pipelines and REST services to ensure scalability and low-latency performanceCollaborate with business stakeholders to translate analytical insights into actionable recommendationsWhat we expect5+ years of professional experience in Data Science or ML Engineering, including production deploymentsMSc or PhD in Computer Science, Statistics, Mathematics, Physics, or related technical fieldStrong Python programming skills, including software engineering practices (OOP, modular code design, testing)Solid experience with ML frameworks and NumFOCUS stack: pandas, scikit-learn, SciPy, Matplotlib, NumPyHands-on experience with PySpark and large-scale data processingFamiliarity with Azure cloud ecosystem (Databricks, ML Studio, Data Factory, Azure DevOps)Understanding of CI/CD and MLOps pipelines, containerization (Docker, Kubernetes), and model deploymentExperience designing robust validation and monitoring strategies for ML models in productionStrong analytical mindset, excellent problem-solving skills, and the ability to think critically about model behaviorFluency in English (spoken and written), as you’ll collaborate globallyNice to haveExperience with Infrastructure as Code (Terraform)Familiarity with DBT for data transformationKnowledge of deep learning frameworks (TensorFlow, PyTorch)Experience working in agile, cross-functional environmentsExposure to multi-tenant or global-scale data systemsIn shortWe’re looking for a Senior Data Scientist who’s not just great at modeling — but who writes clean, production-ready Python, builds pipelines that last, and obsesses over model robustness, automation, and stability.You’ll join a team where experimentation meets engineering — and where your models will directly shape global business decisions.Please add to your CV the following clause:'I hereby agree to the processing of my personal data included in my job offer by hubQuest spółka z ograniczoną odpowiedzialnością located in Warsaw for the purpose of the current recruitment process.”If you want to be considered in the future recruitment processes please add the following statement:'I also agree to the processing of my personal data for the purpose of future recruitment processes.”