Hosty, an engineer with nearly four decades of experience, specializes in the study, implementation, and management of drinking water networks. According to his CV, he began his classical studies at Les Gonaïves with the Brothers of Christian Instruction from 1962 to 1968. After earning his primary education certificate, he moved to Port-au-Prince to continue his secondary education, graduating from the Petit Séminaire Collège Saint Martial in 1976.

Upon completing his secondary education, he entered the Faculty of Sciences at the State University of Haiti (UEH). In 1980, Raphaël Hosty graduated with a degree in civil engineering, bolstered by various experiences, including an internship at the Department of Agriculture, Natural Resources, and Rural Development on an irrigation project in the Artibonite Plain from June to September 1978. Three months after obtaining his degree, Hosty began his professional career working on the Kenscoff water network. Years later, he was promoted to regional engineer for Artibonite and the Northwest, supervising and controlling all work executed by NGOs in the region.