Senior/Lead Data Scientist (Fraud)

TL;DR

Senior/Lead Data Scientist (Fraud): Rebuilding fraud detection systems from the ground up, from raw data to production models, with an accent on converting rules-based systems into model-driven architectures. Focus on building end-to-end ML pipelines, implementing graph networks and anomaly detection, and ensuring low-latency production deployment.

Location: London

Salary: £81,425 - £116,438

Company

hirify.global is a global fintech company that operates with a startup mindset, emphasizing fast decisions and real ownership.

What you will do

• Build best-in-class machine learning systems from the ground up, owning the pipeline from raw data to production.
• Convert existing rules-based fraud systems into sophisticated, model-driven architectures at scale.
• Develop infrastructure from scratch for real-time or near-real-time inference systems.
• Translate ambiguous business problems into technical solutions using graph networks and behavioral signals.
• Collaborate with engineers, analysts, and commercial stakeholders to create real business impact.

Requirements

• Full-stack ML ownership: data engineering, feature development, model design, and low-latency deployment.
• Proven track record of building ML models and pipelines from scratch.
• Experience with real-time inference systems and large-scale datasets (hundreds of millions of transactions).
• Strong proficiency in Python and SQL, with hands-on experience in scikit-learn, LightGBM, Docker, and Jenkins.
• Quantitative degree in Computer Science, Physics, Mathematics, Software Engineering, or a related field.
• Location: Must be based in London

Nice to have

• Experience building end-to-end ML systems in early-stage startups or small greenfield teams.
• Production experience with graph neural networks, anomaly detection, or behavioral biometrics.
• Familiarity with AWS (SageMaker, Lambda, S3, Athena) and CI/CD practices.
• Experience mentoring or technically guiding other data scientists.