High-Level Trigger Calibration Scientist (EP-CMS-TDQ-2026-150-GRAP)

The High-Level Trigger Calibration Scientist will join CERN's Compact Muon Solenoid (CMS) experiment within the Next‑Generation Trigger programme. The position focuses on delivering near‑real‑time, offline‑quality calibrations, so‑called "Optimal Calibrations", to the CMS High‑Level Trigger for the upcoming High‑Luminosity LHC era. Day‑to‑day work involves collaborating with the CMS Detector Performance Groups and Physics Object Groups to create and refine calibration algorithms. You will keep the NGT Demonstrator System running, enable its replay mode on archived data during LS3, and help design a production‑grade NGT Data Acquisition and Calibration System that can operate under various compute and storage scenarios. Integration and testing of the system inside the CMS online infrastructure, close cooperation with system administrators and software engineers, realistic performance simulations, and detailed reporting on the impact of improved calibrations on trigger physics are also key tasks. The role includes supervising a small team. The candidate must hold a Master's or PhD in Applied Physics (or a related discipline) together with the appropriate post‑graduation experience (2‑6 years for a Master's, up to 3 years for a PhD). Proven experience in designing, developing and validating calibration workflows for high‑energy‑physics experiments is essential. Strong programming skills in Python and C++, as well as familiarity with database management systems, are required. Experience with Trigger and Data Acquisition (TDAQ) hardware and tools, practical software‑algorithm development within an integrated framework, and proficient use of GitHub or GitLab together with continuous‑integration practices are also mandatory. Fluency in spoken and written English is required, and the applicant must be willing to work nights, Sundays and official holidays when needed. The position is based at CERN with a hybrid work model and a target start date of 1 January 2027. The contract runs for 24 months, extendable to a maximum of 36 months, at 40 hours per week. Benefits include a monthly net stipend, 30 days of paid leave plus a two‑week annual closure, comprehensive health insurance, pension membership, family allowances, relocation support, and on‑the‑job training including language courses. The team operates in a diverse, inclusive environment that values innovation and collaboration. What the role asks for: - Master's or PhD in Applied Physics (or related) with required experience - Experience designing calibration workflows for HEP experiments - Proficiency in Python and C++ programming - Knowledge of database management systems - Experience with Trigger and Data Acquisition (TDAQ) systems - Proficient with GitHub/GitLab and continuous integration - Spoken and written English - Nice‑to‑have: willingness to learn French