Prior to this, Njoya served in different capacities-including as; interim Team Leader for Governance and Public Institution Pillar in UNDP Liberia (and also as Acting Deputy Country Director for Programmes), Country Programme Specialist and Regional project manager for the Community Security and Peace Consolidation project in UNDP Regional Bureau for Africa, Project  Manager  for the Access to Justice and Rule of Law programme in UNDP South Sudan and as Policy Specialist and Special Advisor to UNDP's Director for the Democratic Governance Group in the Bureau for Development Policy in New York. 
Before joining UNDP, Njoya worked for several years as a practicing corporate and civil litigation attorney in Cameroon and New York . He served as a Senior Human Rights Fellow at the Human Rights Institute,Columbia University School of Law, and as Co-founder and Director for the Centre for Public Interest Law in Cameroon. 
Njoya is a Maurice Greenberg World Fellow at the Jackson Institute for Global Affairs at Yale University, USA. He also holds an LLM in International Contracts and Human Rights Law from Columbia University School of Law, New York, LLM in International Business and financial Regulations from the Central European University, Hungary, and an LLB and Maitrise en Droit from the University of Yaoundé II SOA, Cameroon.