Senior C#/Java developer

About the role

We are looking for an experienced Software Developer proficient in C# and/or Java, to join our team inside the Medical Services department, which contributes to designing complex systems aimed at radiation treatment facilities worldwide. We invite you to check one of our blog posts for you to easier imagine what our software solutions bring to help people.

Key tasks and responsibilities

Developing medical software for cancer treatment systems.
Participating in architecture design, risk analysis, code reviews, and overall teamwork.
Documenting and thoroughly testing your work.
Validating and verifying the work done by the other team members.

Required qualifications and skills

C# and/or Java proficiency and production experience.
Action-oriented and analytical skills.
Understanding of software design, programming techniques, and computer science fundamentals.
Familiarity with source control (Git), CI/CD, code analysis, and other modern programming practices.
Developed communication skills and an open mind for discussion and team collaboration.

Education

B.Sc. in Computer Science, Electrical Engineering, or other related technical disciplines.
Fluency in spoken and written English.

Bonus points if you have

Demonstrated competency in WPF using the MVVM pattern.
Knowledge of other programming languages.
Experience in concurrent and distributed systems.
Understanding of functional programming.
Linux / *nix user experience.

What we offer

Employment contract for an indefinite period with a six-month probationary period.
A work environment with flexible working hours and a hybrid work model.
Plenty of personal and professional growth opportunities combined with a competitive and periodically updated salary tailored to your skills, experiences, and results.
Interesting work full of challenges in an international working environment.
Opportunities to work abroad.
High-impact learning culture: regular in-house and external training sessions and a team of international professionals eager to help you grow.
Many recreational after-work activities, additional health insurance (Specialists+), unlimited coffee, soft drinks, fruit, and other well-being goodies.
Cosylab events (Teambuilding, New Year’s Party, Picnic … ).

Why join Cosylab?

We are the leading software solutions provider for the world’s most complex, precise, and advanced systems, such as particle accelerators, large telescopes, fusion reactors, innovative medical devices, and cancer treatment systems. Our technology enables organizations to make scientific discoveries, offer the most cutting-edge cancer treatments, innovate in healthcare, and introduce clean fusion energy to future energy markets.

Working at Cosylab is a great opportunity to discover genuine teamwork and collaborate with experts from the world’s most important research projects. We value and strive to achieve good interpersonal relationships and try to ensure the pleasant well-being of all our employees. We are friendly, proud to work together, and able to develop just about any solution we put our minds to.

Cosylab culture

Our values

We offer the best solutions for ambitious businesses.

Think bold

We deliver exceptional solutions through courageous thinking, open communication and the drive to continuously improve.

Be modest

We set our egos aside in actively listening, respecting one another, and embracing the diversity of experience and perspective across the company.

Work smart

We know we get more accomplished by working together, being accountable, focusing our efforts and going the extra mile.

Enjoy life

We prioritize balance and positivity, nurturing personal wellness and celebrating successes.

Do good

We support one another and are passionate about solving the difficult problems that ultimately help make the world a better place.

Discover our work environment

Apply for Senior C#/Java developer by Tuesday, November 20, 2025

Please fill in the application form and upload your English CV, motivational letter and other relevant documents.

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I hereby give my consent to Cosylab d.d., and if the application pertains to a job position at Cosylab d.d.'s subsidiary, to said subsidiary (both together referred to herein as 'Cosylab'), for processing my personal data for the purpose of selection and employment (please select YES or NO).

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Processing of personal data for the purpose of statistical analysis of received applications (education, age etc.) for 24 months:

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Entry of my application and submitted documentation into Cosylab’s candidate database (“talent pool”) for future job openings and contact purposes:

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By submitting this form, I acknowledge that I am aware of the personal data collected and processed about me by Cosylab. I confirm that I have reviewed the Recruitment Privacy Policy of Cosylab, which is available on the Cosylab d.d. website, and understand my right to withdraw my consent, in whole or in part, at any time by submitting a written request to dpo@cosylab.com. By applying to this position and submitting my application, including my resume, cover letter, motivational letter, recommendation letters, and any other documentation demonstrating my qualifications (such as proof of education and professional experience), I hereby consent to the processing of my personal data by Cosylab for the purpose of evaluating my suitability for the relevant position.

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Please fill in the application form and upload your English CV, motivational letter and other relevant documents.

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