[1] After his studies at the École nationale d'administration, Roussely became an auditor in 1978 and subsequently became a referendum advisor at the Cour des Comptes in 1982 in the cabinet of Minister of the Interior Gaston Defferre.
He held various positions in Defferre's successor, Pierre Joxe's cabinet as well, including his service as Chief Executive Officer of the Directorate General of National Police [fr] from 1989 to 1991 and as Secretary-General for the Administration of the Ministry of Armed Forces from 1991 to 1997.
[2] Additionally, he served on the nuclear energy committee of the French Atomic Energy Commission from 1991 to 1997 and was director of the civil and military cabinet of Defense Minister Alain Richard from 1997 to 1998.
He also served as Vice-President of Credit Suisse in Europe.
[3] Roussely died on 11 January 2023, at the age of 78.