SW Developer / Experimental Physicist

Job Posting Organization:
CERN, the European Organization for Nuclear Research, was established in 1954 and is one of the world's largest and most respected centers for scientific research. With over 2,500 employees and thousands of scientists from around the globe, CERN operates in multiple countries, fostering collaboration and innovation in the fields of physics and engineering. The organization is dedicated to pushing the boundaries of knowledge and technology, focusing on understanding the fundamental particles and forces that shape our universe. Diversity and inclusion are core values at CERN, ensuring that every team member's contribution is valued and that a collaborative environment is maintained.

Job Overview:
The position of SW Developer / Experimental Physicist is integral to the ATLAS Trigger and Data Acquisition (TDAQ) system at CERN. The Event Filter (EF) is a critical component that processes data from high-energy physics experiments, particularly during the high-luminosity conditions expected in Phase-II operations. The successful candidate will engage in research focused on applying machine learning (ML) techniques to enhance track reconstruction processes within the EF. This role is part of the Next Generation Trigger programme, which aims to innovate and improve the efficiency of data processing in high-energy physics experiments. The candidate will work closely with the ATLAS team to explore and implement promising ML approaches, contributing to both the physics and computational performance of the EF tracking workflow.

Duties and Responsibilities:
The responsibilities of the SW Developer / Experimental Physicist include conducting in-depth research on machine learning and AI-based methodologies for track reconstruction, particularly in the challenging high pile-up environment of the HL-LHC. The candidate will benchmark novel ML-based tracking algorithms and assess their integration into the ACTS-based EF tracking workflow. Additionally, the role involves contributing to studies that evaluate both the physics performance and computational efficiency of various configurations under consideration. The position also includes team supervision responsibilities, requiring the candidate to lead and guide team members effectively.

Required Qualifications:
Candidates must possess a professional background with a PhD in Particle Physics, Computer Science, or a related field. Alternatively, a Master's degree accompanied by 2 to 6 years of relevant post-graduation professional experience is acceptable. It is essential that candidates have not previously held a CERN fellow or graduate contract. The ideal candidate will have a strong understanding of the challenges associated with tracking in high-density environments and experience in developing and applying machine learning or deep learning methods within a scientific computing context.

Educational Background:
The educational requirements for this position include a PhD in Particle Physics, Computer Science, or a closely related discipline. Candidates with a Master's degree and relevant professional experience are also considered. The educational background should reflect a solid foundation in both theoretical and practical aspects of physics and computational methods, particularly as they relate to machine learning applications in experimental physics.

Experience:
The position requires candidates to have a minimum of 2 years of post-graduation professional experience if holding a Master's degree, or up to 3 years if holding a PhD. Experience should include hands-on development of offline and/or online reconstruction software, as well as familiarity with machine learning frameworks and their application in scientific research. Candidates should also have experience with large-scale scientific software frameworks, which is considered an asset.

Languages:
Fluency in spoken and written English is mandatory, as it is the working language at CERN. Candidates are also expected to demonstrate a commitment to learning French, which is beneficial for integration into the local community and workplace.

Additional Notes:
The contract duration for this position is initially set for 24 months, with the possibility of extension up to a maximum of 36 months. The role requires a full-time commitment of 40 hours per week and may involve stand-by duties, as well as work during nights, Sundays, and official holidays as needed by the organization. The job reference for this position is EP-ATL-OSW-2026-121-GRAP. Compensation includes a monthly stipend ranging from 6372 to 7004 Swiss Francs, tax-free, depending on the candidate's qualifications. Additional benefits include 30 days of paid leave per year, comprehensive health insurance coverage, family allowances, a relocation package, and opportunities for on-the-job training and formal education, including language classes.