[1] In November of 2017, he began a one-year term as President of the National Council, succeeding Jürg Stahl.

In 2007, de Buman was president of the organizing committee for the celebration of the 850th anniversary of the city of Fribourg.

From 1991 until 2004 de Buman was chief of staff of the pension fund of the city of Freiburg.

Their poor leadership - the coverage reached only 32% - resulted in the formation of a commission of inquiry, which made de Buman partly responsible for the unfortunate situation.

He did not run for re-election as the bylaws of the Fribourg Christian Democrats impose a four-term limit on its members.