A civil engineer by training, a project manager, and a seasoned consultant in environmental and civil engineering, Mr. Sayinzoga has served as a civil servant (1999–2002), a consultant in the private sector (2002–2007), and a public infrastructure engineer specialist at UNDP (2008–2009).
He also served as Project Manager for the One Dollar Campaign (2009–2012), Project Manager at ADRA Rwanda (2013–2015), and Construction Project Manager Consultant for UNICEF Rwanda.
He has supported various institutions as an expert in real estate audit and conflict resolution. Sayinzoga is a certified valuer and has served as Chairperson of the Disciplinary Committee of the Institute of Real Property Valuers (IRPV), an Associate Member of the Chartered Institute of Arbitrators (ACIArb), and Technical Advisor to the Construction Sector Skills Council (CSSC).
He was elected First Vice Chairperson of TI-Rwanda in March 2015 after serving the organization as a member of the Advisory Council. During the Ordinary General Assembly held on 12 September 2021, Mr. N. Apollinaire Sayinzoga was re-elected for a five-year term as First Vice Chairperson of TI-Rwanda.
At the TI-Rwanda Extra Ordinary General Assembly held on Sunday, 15 February 2026, Eng. Apollinaire Sayinzoga Nkongoli was elected as the new Chairperson of the Board of Directors, succeeding the late Ingabire Marie Immaculée.