Von Ballmoss has been part of the
Young Boys team since he joined in 2007 as part of their youth team. He was promoted into the main team in 2015 and sent on loan to
FC Winterthur in Swiss Challenge League for the 2015–16 and 2016–17 seasons. He has been back at BSC Young Boys since the 2017–18 season and now plays as the main goalkeeper in the Super League. Von Balmoos made his professional debut for
Young Boys in a Swiss Super League 2–0 win over
Basel on 22 July 2017. On 8 September 2025, he joined league rivals
FC Lugano on loan for the
2025–26 season, with an option for a permanent transfer. ==International career==