Bosire holds a Bachelor of Laws degree from the University of Nairobi, a Master of Laws from the University of Auckland and is a PhD researcher at the University of Groningen, where he is researching on the international taxation of private equity funds. Bosire is a lecturer at the Department of Commercial Law, University of Nairobi, where he teaches, researches and writes on taxation and international investments. In addition to his role as a lecturer, Bosire is a member of the Faculty of Law’s research committee. He has taught at Massey University, New Zealand and Jomo Kenyatta University of Agriculture and Technology, worked as a tax adviser at Deloitte & Touche and PricewaterhouseCoopers and practiced commercial and tax law at Iseme, Kamau & Maema Advocates (DLA Piper) in Nairobi. His principal focus is tax law but has a continuing interest in related areas of budgeting law and policy, interaction between taxation and, respectively, international investments and accounting.

Bosire is a member of the Law Society of Kenya and the Institute of Certified Public Accountants of Kenya.