Klarna

Klarna

London

Senior/Lead Data Scientist - Credit

Full-Time£48,000 - 70,000 per yearhace 3 díasUnited Kingdom
IT

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
Responsibilities:
  • 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
Technologies:
  • 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

Klarna

London

IT

Skills & Technologies

PythonGoRESTMachine LearningAIPyTorchUI

Inferred from job description

Salary Insight

£59,000

This role

£75,000

UK median

This salary is 21% below the UK median for Senior roles75,000/yr).

Based on 2024–2025 UK technology sector benchmarks

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