Detect fraud in milliseconds, at the moment a transaction happens, without blocking legitimate customers.Machine Learning Engineer - SpainMadrid or Barcelona, Spain · Permanent · HybridWhat you'd actually work on- Building and maintaining fraud detection and risk-scoring models used on live transactions- Developing features from transactional, behavioural, account, and device data- Training and evaluating models against new and evolving fraud patterns- Deploying models into low-latency production systems- Reducing false positives while maintaining effective fraud detection rates- Working with risk specialists to translate fraud scenarios and business rules into model features- Designing feedback loops using confirmed fraud cases, manual reviews, and transaction outcomes- Monitoring model performance, feature quality, drift, latency, and prediction distributions- Investigating model degradation and changes in customer or fraud behaviour- Improving model deployment, versioning, retraining, and rollback processes- Documenting model behaviour and decisions for engineers, risk teams,



and auditors- Contributing to code reviews, automated testing, CI/CD, and ML engineering standardsWhere it gets technically interesting- Real-time inference under strict latency constraints, with decisions required before transactions are completed- Highly imbalanced datasets where confirmed fraud represents only a small proportion of all transactions- Fraud patterns that change deliberately in response to existing detection methods- Managing delayed or incomplete labels when transaction outcomes are not immediately known- Balancing fraud detection rates against the commercial and customer impact of false positives- Identifying drift in models and features before it results in significant financial losses- Combining machine learning outputs with business rules and manual risk controls- Meeting explainability and traceability requirements for decisions that may need to be reviewed later- Roll

📌 Machine Learning Engineer (España)
🏢 The French Sourcer
📍 España