Junior Python Developer (BE-CSS-GTA-2025-83-GRAE)

Job Description

Your responsibilities

Are you a skilled Python developer with a passion for creating intuitive and robust graphical interfaces? Join the  BE-CSS-GTA team team and contribute to the design and development of PyUI, a Python-based UI framework using PyQt, and a GUI applications that will run on it: the Sequencer UI for CERN’s particle accelerator operations.

In this role, you will: 

• Help design and implement PyUI, a development environment supporting PyQt GUIs with accelerator-specific components.
• Develop the new Sequencer UI for editing and executing operational sequences, using PyUI as a base.
• Work closely with users to gather and refine requirements, then turn them into working applications.
• Create demos, examples, and documentation to support PyUI adoption by other developers.
• Collaborate with a team of experienced Python developers and UI designers to bring modern software practices to the accelerator control domain.
• Support the validation and evolution of PyUI based on real-world application feedback.

Your profile

Skills

• Experience with Python 3.
• Knowledge of PyQT (or Qt).
• Previous experience in UX would be an asset.
• Spoken and written English or French, with a commitment to learn the basics of the other language.

Eligibility criteria:

• You are a national of a CERN Member or Associate Member State .
• By the application deadline, you have a maximum of two years of professional experience since graduation in Software Engineer (or a related field) and your highest educational qualification is either a Bachelor's or Master's degree.
• You have never had a CERN fellow or graduate contract before.
• Applicants without University degree are not eligible.
• Applicants with a PhD are not eligible.

Additional Information

Job closing date: 08.07.2025 at 23:59 CEST.

Contract duration: 24 months, with a possible extension up to 36 months maximum.

Working hours: 40 hours per week

Target start date: 01-August-2025

Job reference: BE-CSS-GTA-2025-83-GRAE

Field of work: Software Engineering and IT

What we offer

• A monthly stipend ranging between 5196  and 5716  Swiss Francs (net of tax).
• Coverage by CERN's comprehensive health scheme (for yourself, your spouse and children), and membership of the CERN Pension Fund.
• Depending on your individual circumstances: installation grant; family, child and infant allowances; payment of travel expenses at the beginning and end of contract.
• 30 days of paid leave per year.
• On-the-job and formal training at CERN as well as in-house language courses for English and/or French.

About us

At CERN, the European Organization for Nuclear Research, physicists and engineers are probing the fundamental structure of the universe. Using the world's largest and most complex scientific instruments, they study the basic constituents of matter - fundamental particles that are made to collide together at close to the speed of light. The process gives physicists clues about how particles interact, and provides insights into the fundamental laws of nature. Find out more on http://home.cern.

Diversity has been an integral part of CERN's mission since its foundation and is an established value of the Organization. Employing a diverse workforce is central to our success.