Klarna
Senior/Lead Data Scientist - Credit
Job Description
Salary: £48,000 - 70,000 per year
Requirements:- Deep understanding of transformer architectures and sequence modelling, with the ability to reason through architectural trade-offs
- Hands-on experience designing tokenisation schemes for heterogeneous feature types such as numerical, categorical, and temporal data
- Proficiency in Python, PyTorch, SageMaker, and Airflow
- Experience owning the full model lifecycle, from training through to serving in production
- Comfortable working in a small, high-ownership team on open-ended technical problems
- Experience with Triton kernels or GPU-level optimisation
- Broader ML background spanning areas beyond deep learning
- Experience with large-scale transactional or financial data
- Background in ML infrastructure or MLOps
- Work on technically interesting modelling problems in fintech, training large transformer-based models on long sequences of real-world transactional events
- Design tokenisation schemes for numerical, categorical, and temporal features
- Make deliberate decisions about vocabulary size, sequence length, and information compounding
- Work across the full model lifecycle, from data preparation through to production
- Translate research decisions into systems that set the direction for how machine learning operates across our company
- Contribute as part of a small, high-ownership team where your work has genuine impact on the products we ship
- Airflow
- Machine Learning
- PyTorch
- Python
- MLOps
More:
We are a fintech company based in London offering a full-time role with a salary range of 81,425 to 116,438 GBP. We are looking for someone to join a small, high-ownership team working on impactful machine learning systems and large-scale modelling problems. The role involves end-to-end work across research, training, and production, with opportunities to shape how machine learning operates across our products. Candidates should include a CV in English.
last updated 34 week of 2026
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About Klarna
Klarna
London
IT
Skills & Technologies
Inferred from job description
Salary Insight
£59,000
This role
£75,000
UK median
This salary is 21% below the UK median for Senior roles (£75,000/yr).
Based on 2024–2025 UK technology sector benchmarks