Siersdorfer joined Siemens in 1987 and assumed his current role at Siemens Energy in 2020 following the company’s spinoff from Siemens. In April 2024, he was appointed managing director for Africa. Siemens Energy and Qatar Free Zones Authority signed an MoU in May 2024 to establish a maintenance and repair center for rotating equipment in the Qatari free zone. Siersdorfer is chairman of the board of Siemens Electrical and Electronic Services in Kuwait, and Siemens Energy Egypt.