SW Developer / Experimental Physicist (EP-ATL-OSW-2026-121-GRAP)

• Conduct research on machine learning (ML) and AI-based approaches for track reconstruction, with a focus on the applicability and performance of these methods in the high pile-up environment of the HL-LHC.
• Investigate and benchmark novel ML-based tracking algorithms and their integration into the ACTS-based EF tracking workflow.
• Contribute to studies of both physics performance and computational performance of the different configurations under study.
• This role includes team supervision responsibilities.

• Understanding of tracking challenges in high track density environments, such as at the High-Luminosity LHC.
• Experience in the development and application of machine learning or deep learning methods in a physics or scientific computing context.
• Hands-on experience in the development of offline and/or online reconstruction software.
• Ability to lead teams and define directions.

Skills:

• Machine learning and deep learning frameworks.
• Experience with ML inference deployment.
• Knowledge of ML model training, evaluation, and optimisation, including hyperparameter tuning and performance benchmarking.
• Programming languages: C++ and Python, including software development workflows (Git, Jira).
• Experience with large-scale scientific software frameworks (e.g. ACTS, Athena) is considered an asset.
• Spoken and written English, with a commitment to learn French., * You have a professional background in PhD in Particle Physics / CS (or a related field) and have either:

• a Master's degree with 2 to 6 years of post-graduation professional experience;
• or a PhD with no more than 3 years of post-graduation professional experience.

• You have never had a CERN fellow or graduate contract before.

• A monthly stipend between 6372-7004 Swiss Francs per month (tax free) depending on your degree.
• 30 days of paid leave per year plus 2 weeks annual closure.
• Coverage by CERN's comprehensive health insurance scheme (for yourself, your spouse and children), and membership of the CERN Pension Fund.
• Family, child and infant monthly allowances depending on your individual circumstances.
• A relocation package (installation grant and travel expenses) depending on your individual circumstances.
• Possibility to extend your contract up to 36 months.
• On-the-job and formal training including language classes.

Imagine taking part in the largest scientific experiment in the world. CERN needs more than physicists and engineers - if you're a student, a graduate, just starting your career or an experienced professional, whatever your field of expertise, CERN could be your next opportunity.