Giant Leap Trainee, Data Scientist

Location: Harpenden, GB

Are you ready to take a Giant Leap? We’re looking for a Data Scientist Trainee for our Giant Leap program – a project-based internship in our Harpenden Office, UK. You will join our Vaisala Xweather team specialised in Finance and Insurance to enhance our Weather Data Cleaning Systems. This position is central to our operations, focusing on the creation and maintenance of high-quality datasets used by the weather risk management trading community.

As a Giant Leaper, you will get your own project to lead for three months, starting in June.

Vaisala is a global leader in measurement instruments and intelligence helping industries, nations, people, and the planet to thrive. From predicting hurricanes to optimizing renewable energy production, our technology is used where it matters the most – from data centers, windfarms and laboratories to airports, the Arctic and even the surface of Mars. Vaisala is recognized in TIME Magazine’s "World’s Best Companies in Sustainable Growth 2025" study. Our team of over 2,400 experts and 59 nationalities around the world is committed to taking every measure for the planet. Driven by our shared purpose, curiosity, and pioneering spirit, we stay ahead and make a difference. At Vaisala, you don't have to fit in to belong.

Giant Leap is a unique opportunity for you to be the project manager of your own project, with the support of your teammates and project supervisor. Every year, these projects are carefully selected by our leadership teams, meaning that you get to work on real‑life questions that are important for us as a company.

We invest in your growth with training sessions throughout the summer. Along with lessons from your own field and work life in general, you have a chance to learn, for instance, presentation skills, project management and problem solving. Connections built with fellow Giant Leapers, Vaisala’s brilliant experts and our leadership form an invaluable network for your career. Many of our former Giant Leapers have also gone on to build impressive careers at Vaisala after the program.

As a Junior Data Scientist trainee or a Meteorologist with significant Data Scientist experience trainee, you will help in advancing our applied machine learning capabilities to clean Historical Weather Data. You will focus on exploring and developing new features, testing a variety of modeling approaches, and supporting innovation in how we use supervised learning for complex time‑series and structured data challenges.

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• Develop, improve and automate Data Cleaning Techniques, ensuring high accuracy and reliability.
  
• Experiment with a range of modeling techniques for the various weather variables: temperature, rain, wind, etc.
  
• Collaborate with software developers to integrate promising approaches into larger workflows.
  
• Automate clients’ data cleaning techniques used as an input to ML models.
  
• The role will be predominantly office based.
  

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• Knowledge of meteorological datasets
  
• Hands‑on experience with machine learning libraries (scikit‑learn, XGBoost, PyTorch, TensorFlow, or similar).
  
• Familiarity with statistical methods.
  
• Proficiency in Python, with strong analytical and data manipulation skills.
  
• Familiarity with software development, ideally in C#.
  
• Excellent communication skills for liaising with internal teams and external stakeholders.
  
• While the core modeling is in Python, you will need to integrate your Python models/APIs with existing C#/.Net applications.
  

Are you ready to take a Giant Leap?

Please apply by February 8, 2026, and include your CV.
We’d also love to hear what inspired you to apply for this role and to Vaisala in a brief cover letter.

If you want to know more, feel free to reach out to the hiring manager / project supervisor Michael Moreno via email . Please note that applications sent via email cannot be processed due to privacy reasons.

Kindly note that we are not able to provide support in relocation or work permit‑related applications.