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Starting off as a physicist, Axel studied physics and math in Muenster, Germany. In 2000, he got a Ph.D. position for high energy physics in Nijmegen, The Netherlands. They sent him to Fermilab at Chicago, where he worked with the DØ experiment - which also meant writing software from PCI drivers to data analysis code. During that time he got involved with ROOT, converting from a user to a developer. He contributed to whatever he needed, e.g. the statistics part, the documentation engine, and porting it to cygwin. After a position with the Fermilab Computing Division in 2005 he ended up at CERN in the ROOT development team. Axel is leading the ROOT project since 2017.

Bertrand was primary working in Aluminum industry as process engineer, developing software for data acquisition, data analysis, statistical process control (SPC) and for X-Ray spectrometry. He has been involved in ROOT development since 2001 by porting ROOT to Windows. Bertrand is a member of the ROOT development team at CERN since August 2005. He's currently working on GUI (Graphical User Interface), core (mainly Windows support), and JavaScript Root (JSROOT).

Danilo is a particle Physicist and scientific software enthusiast. He obtained his Ph.D at the Karlsruhe Institute of Technology, Germany. He joined CERN as member of the CMS collaboration, to then move to the SFT group in 2012. He is a member of the ROOT team since 2013 and contributed to many of its areas: I/O, reflection, math and statistics. He is mainly involved in the aspects of ROOT which are relative to parallelism, performance and programming model.

Enric Tejedor received his Ph.D. from the Technical University of Catalonia (UPC, Spain) in 2013. He conducted his doctorate research as a member of the Grid Computing and Clusters group of the Barcelona Supercomputing Center, where his researched focused on parallel programming models for distributed infrastructures and where he participated in several EU research projects. As part of his Ph.D., he also carried out two internships at the IBM T.J. Watson Research Center (NY, USA). In 2015 he joined the CERN EP-SFT group as a senior fellow and later became a staff member. He is currently working on ROOT parallelization, the ROOT Python bindings and the SWAN service. He is also one of the administrators of the Google Summer of Code student program (GSoC) at CERN-HEP Software Foundation.

Enrico is a physicist turned computer scientist. His first experience at CERN was as Openlab summer student in 2015, experience during which he worked on multi-process analysis interfaces for ROOT. In 2016, he graduated cum laude from the Department of Physics of the University of Milan. His master's degree focused on statistical physics and computational methods for physics. In 2016, he joined the ROOT team as a computer science doctoral student, funded by the Wolfgang Gentner Scholarships programme. His most relevant contributions to ROOT have been in the areas of data analysis performance and programming model.

Guilherme has always been at the interface between physics and computer science. He started his undergraduate studies in computer science at the University of São Paulo (USP) campus in São Carlos in 2000, but later moved to the São Paulo campus for the course of molecular sciences, a special interdisciplinary program of the university aimed at preparing students for scientific research. In 2004, he moved to Japan for his master degree in nuclear physics at the University of Tokyo, where he studied the elastic and inelastic scattering of ⁷Be+p. He then moved on to obtain his PhD in aerospace engineering from the University of Illinois at Urbana-Champaign, USA. Guilherme then worked for two years at São Paulo State University (UNESP) in collaboration with CERN and Fermilab before joining the ROOT Team in April of 2017. His responsibilities in ROOT include working on the build system, performance analysis and optimization, and support for SIMD vectorization.


Jakob joined CERN for the first time as a summer student in 2007. He graduated from the University of Karlsruhe and obtained a PhD in computer science from the Technical University of Munich. Jakob works on distributed systems and storage software. He created the CernVM File System, which he evolves ever since. Jakob has been a Marie Curie fellow and a visiting scholar at the RAMCloud research group at Stanford University. In the ROOT team, Jakob works on the columnar data storage for event data, searching for ever faster and more robust ways to read and write hierarchically nested ntuples.

Lorenzo started working in 1989 as an experimental physicist for the ALEPH experiment working for data analysis and software event reconstruction. He graduated in Pisa in 1990 and he received his Ph.D. in particle physics in 1994 at the University of Florence. Afterwards, since 1997, he was working for data analysis of the CDF experiments and online software for the ATLAS experiment. In 2002 he joined the physics application software group of CERN, and since 2005 he joined the ROOT team with the responsibility of the Math work package, which provides development and support for the ROOT mathematical and statistical libraries. 

Currently, I am employed as a software developer from the University of Nebraska-Lincoln (CMS), based at CERN and working as a core developer in the ROOT framework. My area of research is a various improvement for ROOT I/O, particularly ROOT compression algorithms. Another area of investigation is work on improved ROOT modularity for the build system. I was involved in support of C++ modules in ROOT and performance benchmarking of ROOT.

I did my doctoral studies in Simulation group at CERN, working in GeantV project (EP-SFT, CERN). Previous work experience was a long term work in Ukrainian Grid Initiative on various positions, including responsibilities on grid sites management and experiment support, administration, and security management.

Olivier Couet received a Physic's Master from the  Strasbourg University and a Master’s Degree in Engineering from the "Ecole Nationale Supérieure de Physique de Strasbourg" (ENSPS) on work in computer graphics and image processing in 1985. He then performed his Ph.D work (in Computer Graphics) at the "Laboratoire D'Annecy le Vieux de Physique des Particules" (LAPP) on the PAW project. He has been employed by CERN since 1988. He was one of the main authors of the PAW system, more precisely its graphical components (HIGZ and HPLOT). HIGZ has been the standard graphics package in High Energy Physics for years and is still being used. He was responsible for the PAW system from 1995 until he joined the ROOT team in 2002 and took responsibility of the graphics work package.

Philippe Canal has been working in the FNAL Computing Division since 1995. Philippe graduated from Ecole Centrale Paris and has a Master in Computer Science from Northwestern University. Philippe is responsible for the development of the I/O sub-system and the Tree query mechanism and oversee the overall architecture of ROOT.  Philippe coordinates the support for ROOT for all FNAL experiments.

Sergey Linev was graduated from the Nuclear Physics Department of Belorussian State University, where he also received his Ph.D. in Physics and Mathematics in 1999. Since 2002 Sergey working in GSI - heavy-ion research center in Darmstadt, Germany, developing software for data acquisition and online analysis for different experiments. From 2004 starts contributing to different ROOT components like I/O with XML, SQL, JSON, THttpServer, JavaScript ROOT. Currently is responsible for the development of new web-based GUIs in ROOT like RCanvas, REve, RFitPanel and many others.

Stephan is a particle physicist, and obtained his Ph.D. at the university of Bonn in Germany. He worked in ATLAS to improve the sensitivity in the search for Higgs --> bb decays. His main focus was on analysis frameworks, machine learning, systematic uncertainties and statistical models. He joined the ROOT team in 2018 to support and improve RooFit. He further looks into math and statistics, as well as into questions regarding performance and programming model.

Vassil graduated from the University of Plovdiv "Paisii Hilendarski", Bulgaria. He received a MSc in Software Technologies and a PhD in Computer Science with specialization in programming languages and visual programming. He joined the ROOT team in 2010, authoring Cling - the interactive, LLVM-based C++ interpreter. He was one of the core engineers involved in ROOT6.

Vassil is responsible for the implementation and adoption of clang's C++ modules (PCMs) in ROOT. He also helps with interpreter and reflection related activities in the ROOT project. He works on the CMS interests in the ROOT collaboration including development, trouble shooting, and any other activities as may be required.   

From January, 2017, Vassil is employed by Princeton University and part of the Princeton Intel Parallel Computing Center (IPCC) project, which focuses on code modernization in ROOT.