R D Software Developer C++/Python (EP-SFT-2025-45-GRAE)

von: CERN

Your responsibilities

Are you software engineer interested in data science and physics, or a physicist or data scientist specialising in software development? Do you like to craft robust and performant software components at the heart of large scientific software stacks?

We at ROOT are convinced that using C++ for performant algorithms and Python for ergonomic user interface is a future-proof approach to scientific data analysis. Join the ROOT team ( to become an R & D developer on ROOTs C++ to Python interoperability today, supported by the CERN EP R & D program. In particular, you will:

• Update ROOTs Python bindings to build on top of newest LLVM/Clang technology to unlock new features.
• Ensure that the algorithms in ROOT can be used in an ergonomic way from both C++ and Python.
• Take part in the baseline support, modernization and maintenance tasks of the project.

More information here:

Your profile

Skills

• C++ (C++17 and onwards, STL data structures and algorithms)
• Software development with Python 3
• Knowledge of the API of the Clang C++ compiler
• Basic understanding of the Python C API
• Knowledge of interoperability layers between Python and C++
• Working on open source projects, also private (e.g. knowing git and how to work on a large codebase in a team) is considered an advantage

Optional, but considered a plus:

• ROOT
• Experience in scientific data analysis
• Knowing the software stacks and workflows of particle physics experiments

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 Computer Science, Software Engineering (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: 02.04.2025 at 23:59 Hrs CET.

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

Working hours: 40 hours per week

Target start date: 01-June-2025

Job reference: EP-SFT-2025-45-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

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.