Assomo graduated from the Grenoble School of Architecture in 1996 and worked as a researcher there at the Centre for Earthen Construction.[1] Early project he worked on were praised by Nelson Mandela for their community-centred approaches.[2] He joined UNESCO in 2003 and worked on the implementation of the African World Heritage Fund,[1] and the World Heritage Earthen Architecture Program.[3]
From 2008 to 2013, he led the Africa Unit of World Heritage Centre, and from there joined UNESCO's Bamako office,[4] and in 2014 was appointed to lead its Mali office.[1] He worked on the reconstruction of mausoleums in Timbuktu that were destroyed by al-Qaeda.[5] In 2016 he returned to the World Heritage Centre as Deputy Director of the Heritage Division, before being appointed in 2018 Director of Culture and Emergencies.[1]
In December 2021, he was appointed Head of the World Heritage Centre by Audrey Azoulay, replacing Mechtild Rössler.[3] He is the centre's fifth director and the first African to hold the position.[6][5][7] He has been outspoken on the subject of the study of "colonial heritage" in Africa.[8]