Christian Veelken
Data Preparation Engineer
Hamburg, Germany
Summary
👤
Senior🎓
Top SchoolChristian Veelken is a Data Preparation Engineer with 12 years of experience combining particle physics research and production software development, currently improving additive-manufacturing part quality at Nikon SLM Solutions. He holds a PhD from Liverpool and contributed to the discovery and detailed study of the Higgs boson through roles at École Polytechnique, CERN and UC Davis, specializing in tau reconstruction, MET calibration and mass-reconstruction algorithms. Skilled in C++ and Python, he builds analysis frameworks and ML solutions—Boosted Decision Trees and custom neural nets that incorporate physics symmetries—for signal/background separation and object ID. He has led tau and physics-object groups in CMS and served as PI for ttH and di-Higgs analyses, bringing project management experience to technical teams. An active open-source contributor, he has made targeted backend improvements to CMS nanoAOD tools and core CMSSW tau-reconstruction code, translating collider-grade rigor into industrial data pipelines. Notably, his work often embeds domain-specific physics constraints into algorithm design, yielding robust, interpretable models for noisy measurement environments.
12 years of coding experience
13 years of employment as a software developer
Doctor of Philosophy - PhD, Physics, Doctor of Philosophy - PhD, Physics at University of LiverpoolDiploma, Physics, Diploma, Physics at University of Hamburg
Github Skills (11)
root-view10
c-language10
cprogramming-language10
document-root10
python10
data-analysis9
configuration-management9
algorithms8
data-structures8
algorithm8
data-structure8
Programming languages (5)
Github contributions (5)
cms-sw/cmssw
Oct 2013 - Jan 2021
CMS Offline Software
Role in this project:
Back-end Developer
Back-end DeveloperContributions:3 reviews, 167 commits, 6 PRs in 7 years 3 months
Contributions summary:Christian primarily contributed to the RecoTauTag package within the CMS Offline Software repository. Their work involved modifying and extending the `RecoTauQualityCuts` class and related Python configuration files. They added parameters, improved code formatting, and refactored code to use a new method for declaring configuration parameters. Significant changes were made to incorporate vertex information and address specific performance considerations within the tau reconstruction algorithms.
cmscernweb-appc-plus-plusbackbonejs
cms-nanoAOD/nanoAOD-tools
Oct 2017 - Apr 2018
Tools for working with NanoAOD (requiring only python + root, not CMSSW)
Role in this project:Back-end Developer
Back-end DeveloperContributions:24 commits, 8 PRs, 35 comments in 5 months
Contributions summary:Christian primarily focused on implementing and modifying b-tagging scale factors within the nanoAOD-tools repository. Their contributions involved adding scale factors for jet weights, fixing bugs related to zero-valued btagSF evaluations, and updating the btagSF code to match the latest data and MC versions. They also made related syntax adjustments and addressed comments made on their code.
pythonazerothcorecmsswnanoaodmodular
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.