Senior ML Engineer — Fraud Detection & Production Systems

Mangopay; Warszawa; Hybrid; PLN 180,000 - 300,000; Full time

Job summary

Mangopay is seeking a Senior Machine Learning Engineer to join our Data Science team and help develop and operate fraud prevention solutions. This is a hands-on, end-to-end role combining Data Science with Machine Learning Engineering and Data Engineering.

You will work across the lifecycle of ML solutions, from sourcing data through model development to deployment and maintenance in production. We don't expect you to be an expert in all three disciplines.

Qualifications

• 5+ years of professional experience in Data Science or machine learning.
• Strong knowledge of ML algorithms, statistics, feature engineering, evaluation and validation.
• Excellent Python skills with pandas, NumPy, scikit-learn.
• Strong SQL skills with large, complex datasets.
• Good software engineering practices and maintainable design.
• Willingness to grow in either ML Engineering or Data Engineering.

Responsibilities

• Build and improve fraud detection solutions that help identify fraudulent payments, identity theft, and account takeover.
• Investigate fraud patterns by exploring transactional and behavioural data and turning findings into insights.
• Research new algorithms and data sources, develop and maintain ML models processing millions of transactions.
• Build and maintain data pipelines and datasets supporting feature engineering, model training, and real-time inference.
• Develop and operate production ML services, ensuring reliability, scalability, performance and security.
• Build internal tools and workflow automations to streamline processes and increase efficiency.
• Lead end-to-end data science projects from opportunities to measurable impact on products and clients' bottom line.

Skills

Python

SQL

Machine Learning

Data pipelines

Software engineering

ML lifecycle

English & Polish

Tools

AWS SageMaker

Kubernetes

Docker

CI/CD

Kafka

Terraform

Snowflake

dbt

n8n

Job description

Mangopay is seeking a Senior Machine Learning Engineer to join our Data Science team and help develop and operate fraud prevention solutions. This is a hands-on, end-to-end role combining Data Science with Machine Learning Engineering and Data Engineering.

You will work across the lifecycle of ML solutions, from sourcing data through model development to deployment and maintenance in production. We don't expect you to be an expert in all three disciplines.