Physics Software Developer - Detector Simulation and Event Reconstruction (EP-FCC-2025-242-LD)

Company Description

At CERN , the European Organisation 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. 

Job Description

Introduction

You will consolidate the FCC-PED software activities, with a focus on the area of detector simulation, signal digitization and event reconstruction, in view of enabling (i) FCC-ee detector design optimization during the pre-TDR phase and (ii) submission of detector letters of intent after the FCC approval.

More information can be found here .

Functions

• Drive the support, maintenance, and enhancement of the FCC simulation software ecosystem and reconstruction algorithms, including exploring, validating, and harnessing new technologies that could improve the efficiency of FCC detector simulation and event reconstruction.
• Coordinate contributions to the FCC detector simulation software ecosystem, event reconstruction algorithms, and performance evaluation tools.
• Ensure compatibility/synergy of the required software developments with the evolution of the Key4hep common software ecosystem, which is part and parcel of the FCC software.
• Engage with the worldwide FCC user community, foster collaboration and external contributions to the FCC detector simulation, event reconstruction, and performance evaluation software, and organise relevant support channels.
• Supervise and coordinate tasks in domains relevant to the FCC software activities.

Qualifications

PhD or equivalent relevant experience in the field of Experimental Particle Physics or a related field.

Experience:

Some level of experience in the following areas is mandatory:

• Experience with detector simulation and event reconstruction;
• Familiarity with the programming languages mostly used in High Energy Physics (HEP), primarily Python and C++;
• Competence in using modern HEP software tools, such as ROOT, Geant4 and DD4hep;
• Practical knowledge of tools and methods involved in all phases of modern, collaborative, open-source software development, including design, coding, code reviews, and testing for large-scale scientific software systems;
• Understanding of modern particle detection techniques and knowledge of relevant emerging detector technologies.

Demonstrated experience in the following areas will be considered an advantage:

• Detector R&D, commissioning and/or operation;
• Emerging common tools such as the Key4hep ecosystem;
• Experimental particle physics data analysis.

Technical competencies:

• Knowledge of programming techniques and languages: proficiency in C++ and Python;
• Simulation, design and development of (parts of) detectors;
• Development of application software;
• Re-use, refactoring, integration and porting of existing software;
• Knowledge and application of software life-cycle tools and procedures: and with state-of-the-art software build and deployment tools.

Behavioural competencies:

• Achieving Results: having a structured and organised approach towards work; being able to set priorities and plan tasks with results in mind.
• Learning and Sharing Knowledge: sharing knowledge and expertise freely and willingly with others; coaching others to ensure knowledge transfer.
• Demonstrating Flexibility: adapting quickly and resourcefully to shifting priorities and requirements.
• Communicating Effectively: delivering presentations in a structured and clear way; adjusting style and content to the audience; responding calmly and confidently to questions.
• Managing Self: working well autonomously; taking on activities and tasks without prompting.

Language skills:

Spoken and written English, with a commitment to learn French.

Required documents:

The following documents should be submitted to complete your application:

• A CV in English or French 
• At least two recent reference letters giving an overview of your academic and/or professional achievements.

Additional Information

Eligibility and closing date:

Diversity has been an integral part of CERN's mission since its foundation and is an established value of the Organisation. Employing a diverse workforce is central to our success. We welcome applications from all Member States and Associate Member States .

This vacancy will be filled as soon as possible, and applications should normally reach us no later than 10.12.2025 at 23:59 CET.

Employment Conditions

Contract type: Limited duration contract (5 years). Subject to certain conditions, holders of limited-duration contracts may apply for an indefinite position.

Working Hours: 40 hours per week

Job Flexibility: Hybrid

This position involves:

• Work during nights, Sundays and official holidays, when required by the needs of the Organisation.

Job grade: 6-7

Job reference: EP-FCC-2025-242-LD

Field of work: Applied Physics

Benchmark Job Title: Applied Physicist