After his study Engineering Geology at the TU Delft, Siefko has gained almost 25 years of working experience. The red line is the use of innovative tools such as GIS, remote sensing and the use of smart data processing techniques. He spent the first half of his career mainly on research projects. He has gained much international and geological field experience. The second half of his career was focused on consultancy services. In this advisory role his academic background is very useful. He likes to dive into complex geological issues that have an important social relevance. Examples are risk studies of shale gas, earthquakes in Groningen and geothermal energy. Siefko obtained a PhD at the TU Delft and is Chartered Engineer from the Royal Netherlands Society of Engineers (KIVI).