Stanley Trief began his career with the Vanuatu Department of Customs and Inland Revenue, serving as ICT Officer and later ICT Manager from 2002 to 2010. He subsequently led the Customs Border Control and Enforcement Unit as Manager from 2011 to 2015. Between 2016 and 2018, Stanley managed the Vanuatu ASYCUDA World Project, and since 2019 he has overseen Vanuatu's electronic Single Window Project. His leadership has been central to advancing customs modernisation and digital transformation in Vanuatu.

Stanley holds a Bachelor of Science in Computer Science from the University of Waikato, New Zealand (2004), and a Master of International Customs Law and Administration from the University of Canberra, Australia (2011).