Thomas has a Ph.D. in mathematics from the University of Heidelberg, Germany. He has held academic positions at universities in Germany and the US, specializing in mathematical logic, algebra, and symbolic computation. He went on to pursue a career in scientific software development. Among other things, he was lead mathematician and scientific software developer at Zephyr Associates Inc. (since acquired by Informa Investment Services), where he designed, implemented and maintained the mathematical engine of the StyleADVISOR software. During his tenure at Zephyr, StyleADVISOR became the leading analytics platform for institutional investors, money managers, and financial advisors. Over time, Thomas became increasingly frustrated with the fact that he still could not keep track of the performance of his own financial accounts, or, for that matter, compare it to alternate investment strategies such as index funds. It became clear to him that the issue of measuring performance in the presence of deposits and withdrawals was poorly understood. After looking into the mathematics of it, he conceived of and implemented GreaterThanZero. He has been a happy user since the day he deployed Version 0.1 to the server.
In his spare time, Thomas goes backpacking and tinkers with or plays his guitars.