Management Team

Isabell Weipert, Head of Secondary School

Isabell Weipert studied German and English to become a teacher. Upon graduation she took on a teaching position at a Language Immersion School in North Carolina/USA. In 2012 she joined Phorms Education as the founding Head of Primary School at Josef-Schwarz-Schule. From 2017 to middle of 2019 Isabell Weipert worked as Head of Human Resources for Phorms in Baden-Württemberg and took over the management of our Secondary School starting in school year 2019/2020.

Ruben Ebert, Deputy Head of Secondary School

From September 2019 Ruben Ebert has been the Deputy Head of Secondary School at Josef-Schwarz-Schule. In addition he is responsible for the conceptual and content development of our upper secondary school.
Prior to this, Ruben Ebert was Head of a bilingual grammar school in Stuttgart-Fellbach for five years and, as part of this activity, introduced a programme that combined the international Abitur with the International Baccalaureate. In addition, he taught German and history at private and public schools for many years and was a lecturer at the Institute for Literary Studies at the University of Stuttgart.

Ralf Schönborn, Head of Primary School

After many years in school leadership roles at different schools in both Germany and the USA, Ralf Schönborn started at our JSS as a leadership team member in October 2021. He then took over the position of primary school headmaster at both sites on 1 December last year. Ralf studied social pedagogy and worked in a youth home. His two now big "children", Marie and Frederik, in a way live the same spread as Ralf himself: one leg firmly in Germany (Frederik), the other, at least emotionally, in the USA (Marie). He feels that being allowed to work at the JSS is like winning the lottery.

Lisa Schüfer, Head of Primary School

Lisa Schüfer studied German, Math and Catholic Religion in Ludwigsburg at the University of Education. As a native to Neckarsulm, she enriches the Josef-Schwarz-School Team since 2013. In 2015 she became a member of the Leadership Team and is responsible for all subject teachers and the German department. Beginning in January of 2017 she initially took over the temporary position as Head of the Primary School and is now Head of Primary School.

Lisa Schüfer is currently on parental leave. 

Donat Martin, Head of IT

Donat Martin took over as Head of IT at Phorms Baden-Württemberg gGmbH back in 2020 and is now an integral part of the JSS management team. During his school years in the 1980s, he first came into contact with PCs in the electronics club. In 1993, Donat Martin took his first steps with Microsoft's first operating system, MS-DOS, and gained his first programming experience. After studying programming by correspondence, he completed his expertise with an IT degree in 2013. Donat Martin worked as a self-employed typesetter, database developer, programmer and application developer from 1996 onwards, before first starting at Heidelberg International School in Local IT Support in 2019 and then taking on the IT management of Phorms BaWü gGmbH from 2020.

Thomas Frenzel, Managing Director

Thomas Frenzel holds a degree in business administration. He worked at the publishing house Gruner+Jahr in Hamburg for nine years before joining Phorms in 2009. In addition to his work for Josef-Schwarz-Schule, he is the managing director of Heidelberg International School and he is in charge of new Phorms Education projects.

Petra Siegel, Administration Manager

Petra Siegel trained as an office manager and worked for many years as a management assistant at Kaufland. She is a member of the founding team at Josef-Schwarz-Schule and is responsible for the administration.