Job Description

Your responsibilities

The CMS experiment is enhancing its real-time data processing capabilities in preparation for the High-Luminosity LHC (HL-LHC) era. As part of the NextGen Triggers project, we are seeking an Applied Physicist to develop Structure of Arrays (SoA)-based data layouts for heterogeneous event reconstruction in CMSSW.

This role focuses on implementing advanced C++ metaprogramming techniques (macros, templates, type traits) to optimize GPU memory throughput, data transfer efficiency, and real-time event processing. The developed SoA structures will be integrated into both trigger-level and offline workflows, contributing to the scalability and performance of the CMS software framework.

Key Responsibilities

• Design and maintain SoA-friendly data structures using modern C++ (C++20), metaprogramming techniques (Boost Preprocessor, type traits, templates), and GPU-optimized best practices.
• Integrate SoA data layouts into online event reconstruction algorithms, collaborating with the NextGen Triggers team, CMSSW Framework core team, and reconstruction developers.
• Optimize memory management and data transfer strategies to enhance real-time and offline performance, ensuring efficient GPU coalescence and minimal data copies.
• Work with ROOT developers on RNTuple integration and contribute to software maintainability through rigorous testing, documentation, and design reviews.

Your profile

Skills

• Proficiency in modern C++ (including templates, traits, metaprogramming)
• Familiarity with GPU programming (e.g. CUDA, HIP, Alpaka, etc.).
• Experience with large-scale software frameworks, data-structure optimization, and performance profiling.

Eligibility criteria:

• You are a national of a CERN Member or Associate Member State. A limited number of positions are also available to candidates from Non-Member States
• You have a professional background in Physics, Computer Sc., SW Engineering (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.

Additional Information

Job closing date: 13.03.2025 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-April-2025

Job reference: EP-CMG-DS-2025-23-GRAP

Field of work: Software Engineering and IT

What we offer

• A monthly stipend ranging between 6287 and 6911 Swiss Francs per month (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.

We are on a Quest. A Journey into discovery like no other. Bring your expertise to our unique work and develop your knowledge and skills at pace. Join world-class subject matter experts on unique projects, in a Quest for greater knowledge and deeper understanding.

Begin your CERN Quest. Take Part!

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.