Data Scientist

• Design and validate probabilistic models for an e-commerce platform
• Develop models for dynamic pricing, shipping cost estimation, recommendations, and customer/product segmentation
• Design and implement Bayesian statistical models, including priors, likelihoods, and posterior inference
• Build Markov chain and Hidden Markov Model formulations for sequential and behavioral patterns
• Apply MCMC methods, including Metropolis-Hastings sampling, and validate convergence and sampling quality
• Develop mixture models, particularly Gaussian Mixture Models, for segmentation
• Implement Expectation-Maximization for latent-variable estimation and unsupervised learning
• Collaborate with the solution architect and client's CTO on platform architecture alignment
• Guide backend engineering on production translation, API design, data contracts, and microservice/event-driven integration
• Define model training, validation, versioning, monitoring, drift detection, and retraining approaches
• Partner with delivery and engineering leads to size, sequence, and estimate modeling initiatives
• Document modeling assumptions, methodology, validation results, and handoff guidance

Senior Data Scientist, Statistical Modeling

• Design and validate probabilistic models for dynamic pricing, shipping cost estimation, recommendations, and segmentation
• Design and implement Bayesian statistical models, including priors, likelihoods, and posterior inference
• Build Markov chain and Hidden Markov Model formulations for sequential and behavioral patterns
• Apply MCMC methods, including Metropolis-Hastings sampling, and validate convergence and sampling quality
• Develop mixture models, particularly Gaussian Mixture Models, for customer or product segmentation
• Implement Expectation-Maximization for latent-variable estimation and unsupervised learning tasks
• Collaborate with the solution architect and client's CTO to align model design with platform architecture
• Guide backend engineering on production service architecture, API design, data contracts, and microservices/event-driven integration
• Define model training, validation, versioning, monitoring, drift detection, and retraining approaches
• Collaborate with delivery and engineering leads to size, sequence, and estimate modeling initiatives
• Document modeling assumptions, methodology, and validation results
• Provide handoff guidance for ongoing engineering-team maintenance

Senior Data Scientist, Probabilistic Modeling – Architecture, Adjacent

• Lead consolidation of existing recommendation algorithms into a simpler, coherent recommendation capability
• Implement the client’s existing technical direction and agreed delivery plan
• Review recommendation approaches and rationalise duplication, inconsistency and unnecessary complexity
• Develop, improve and productionise recommendation models for customer and commercial use cases
• Own data and feature development, model development, evaluation, production implementation, monitoring, retraining and ongoing optimisation
• Develop scalable production workloads in Databricks using Python and PySpark
• Refactor exploratory or notebook-based Data Science code into maintainable production implementations
• Apply object-oriented design and software engineering principles to the recommendation codebase
• Create reusable and testable components for candidate generation, scoring, ranking, feature generation and evaluation
• Build automated testing around Data Science and ML code
• Work with engineering and platform teams on production integration while retaining model ownership
• Define and maintain offline evaluation frameworks
• Support online experimentation and measurement of recommendation effectiveness
• Monitor production behaviour and own model quality after launch
• Communicate technical information clearly to client stakeholders and the wider delivery team
• Build credibility with senior client Data Science stakeholders
• Operate independently within the client team
• Communicate progress, risks and technical decisions clearly
• Leave the recommendation capability more maintainable than it was found
• Travel according to project, client and organisational needs, estimated at 0%-15%

Data Scientist jobs in Romania

Senior Data Scientist, Statistical Modeling

Senior Data Scientist, Probabilistic Modeling – Architecture, Adjacent

Lead Data Scientist