Are you ready to power the future with a summer job at the heart of the energy industry? Apply now and join us for an impactful summer 2026! 

About the role

The Fortum Data Science & Optimization team is looking for a Summer Trainee who wants to work together with our 10 Data Scientists, Machine Learning Engineers and Optimization Engineers. Since we are Fortum’s internal Center-of-Excellence, we work with all types of in-house developed ML and optimization applications, such as predictive maintenance in power plants, market forecasting, investment optimization, customer insights, as well as the latest generative and agentic AI concepts. We work on our Databricks, AWS and Azure platforms with the full software development tool kit. As a Summer Trainee, you will take part in our projects helping other specialists in their day-to-day work. It is possible to customize the tasks according to your experience and interests.

About you

We hope that you apply for the position if you are:

• A recent graduate or a student in the final stages of your education in data science, machine learning, computer science, engineering, mathematics, or other relevant field.
• Fluent in written and spoken English, as it is our language for internal communication. Knowledge of Finnish or Swedish is an advantage.
• Proficient in Python programming and have experience with machine learning, either through education or through well-documented personal projects). In addition to these must-haves, it is also an advantage if you have experience with software development practices, cloud development and SQL.
• Eager to learn more and contribute to our purpose: to power a world where people, businesses and nature thrive together.

We offer you

We offer you a perfect opportunity to start your career in data science or machine learning engineering. As our current group is a good mix of talented juniors and highly experienced technical specialists, there is no shortage of guidance. From a technical perspective, we have a wide range of applications, a sophisticated and constantly developing IT infrastructure and huge amounts of data.

During the summer you will:

• Receive an introduction to your tasks and be supported by your team.
• Work with interesting tasks with real responsibility.
• Enjoy a hybrid work model with flexible working hours, allowing you to balance remote and in-office work.
• Learn about our company, the energy industry, and the sustainable solutions that we are working with.
• Network with other trainees.
• Gain valuable experience, that can lead to a career with us. Many of our trainees continue after the summer, working part-time while continuing studies or as thesis worker.

Read more about Summer Energy, our recruitment process and previous summer trainees’ experiences here.

Interested?

If this sounds like the perfect opportunity for you, send your CV through our recruitment tool by February 13, 2026.  For further information about the role, please contact Kristofer Jakobsson, Senior Manager Data Science & Optimization, Kristofer.jakobson@fortum.com, +46725544428.

We encourage you to apply as soon as possible! We will start reviewing applications already during the application period. The job ad will close as soon s the right candidate is found.

Our recruitment process may vary depending on the role, but here’s what you can expect:

• Please apply only with your CV/Resume.
• We use screening questions in the application form to ensure candidates meet the must-have requirements.
• For many roles, we include a digital assessment tool (Assessio) early in the process to make the process fair and unbiased, considering the high volume of applications.
• Some applicants are invited to interviews either via Teams or in person, this stage includes at least one interview with the hiring manager.

The summer trainee period typically runs from May to September.

To be selected for the position, the applicant must go through background clearance and a health examination including drug testing.

We are Fortum

Fortum is a Nordic energy company. Our purpose is to power a world where people, businesses and nature thrive together. Our power generation has one of the lowest specific CO₂-emissions in Europe and our actions are guided by our ambitious environmental targets. We generate and deliver energy reliably and help industries to decarbonise their processes and grow. Our core operations in the Nordics comprise of efficient, low-carbon power generation from renewable energy sources and nuclear sources, as well as reliable supply of electricity and district heat to private and business customers.