Junior Data Scientist

Job Description

We are looking for a Junior Data Scientist to join the CDAIO team within a banking client in their Corporate & Investment Banking area in Madrid. You will contribute to the development, validation, and industrialization of Machine Learning and AI models applied to high-impact business problems.

This is a great opportunity to work in an exciting, fast-evolving AI environment, where modern modeling techniques are actively helping to transform how an investment bank operates—from smarter decision-making and automation to improved risk insights and client-facing capabilities.

You’ll collaborate with data scientists, engineers, and business stakeholders to deliver robust, explainable, and scalable solutions—covering the full lifecycle from problem framing to deployment and monitoring.

 What you’ll do

• Develop/apply state-of-the-art statistical, machine learning, and AI models (supervised/unsupervised, forecasting, NLP, anomaly detection, etc.) for use cases.
• Perform data exploration, feature engineering, and model evaluation using rigorous quantitative approaches.
• Apply best practices in model validation: cross-validation, bias/variance diagnostics, calibration, robustness testing, and sensitivity analysis.
• Implement and maintain reproducible ML pipelines (training, inference, monitoring) with strong software engineering standards.
• Contribute to explainability and governance (e.g., SHAP, feature attribution, stability, documentation), aligned with a regulated environment.
• Present findings clearly to both technical and non-technical audiences; translate business goals into measurable modeling objectives.
• Stay current with modern AI: deep learning, LLMs, representation learning, and emerging tooling; prototype where relevant.

Qualifications

Must-have Requirements:

• Bachelor’s or master’s degree (or final-year student) in Computer Science, Mathematics, Statistics, Physics, Engineering, or related quantitative field.
• Strong foundations in linear algebra, probability, statistics, optimization, and numerical methods.
• Solid programming skills in Python (clean code, testing mindset, packaging basics).
• Hands-on experience with ML libraries such as scikit-learn, and familiarity with at least one deep learning framework (PyTorch or TensorFlow).
• Practical knowledge of model evaluation and metrics (AUC, precision/recall, RMSE, calibration, etc.) and experimentation methodology.
• Experience working with data using pandas/numpy, and querying with SQL.
• Good communication skills and ability to work in collaborative, cross-functional teams.
• Professional working proficiency in English and Spanish

Nice to have

• Previous experience in similar roles.
• Exposure to NLP (transformers, embeddings), LLMs, or generative AI concepts (prompting, fine-tuning basics, retrieval).
• Understanding of MLOps concepts and tools (e.g., MLflow, Docker, CI/CD, model monitoring).
• Experience with cloud platforms (AWS/Azure/GCP) and distributed processing (e.g., Spark).
• Familiarity with Databricks (or willingness to learn it on the job) for collaborative development and scalable ML workflows.
• Familiarity with time series modeling, stress testing, or causal inference.
• Interest or exposure to Corporate & Investment Banking / Global Banking products and processes (e.g., lending, trade & working capital, DCM/ECM, transaction banking) and how data/AI can support them (client analytics, pricing, limits, early warning).
• Knowledge of model risk / governance in regulated industries (documentation, traceability, controls) is a plus.
• Familiarity with Finance analytics concepts such as P&L drivers, balance sheet metrics, FTP, capital/RWA, or management reporting—able to translate financial KPIs into modeling objectives.
• Understanding of Risk fundamentals (credit risk, market risk, liquidity risk, operational risk) and common modeling topics such as PD/LGD/EAD, rating/scorecards, stress testing, early warning signals, or portfolio monitoring in a regulated environment.

Additional Information

What do we offer you?

• Hybrid position based in Madrid, Spain
• Permanent, full-time contract.
• Smart Office Pack so that you can work comfortably from home. 
• Training and career development.
• Benefits and perks such as private medical insurance, life insurance, Language lessons, etc
• Possibility to be part of a multicultural team and work on international projects.

If you are passionate about data, development & tech, we want to meet you !