Lieutenant Colonel Haji Rony Zai bin Haji Zaini began his military career when he enlisted into the Royal Brunei Armed Forces (RBAF) in May 2000. He was commissioned as an Officer in September 2002, after completing his Officer Cadet training at the Army College, Ulu Tiram, Johor, Malaysia.
Throughout his military career, Lieutenant Colonel Haji Rony Zai held various command and staff appointments in the RBAF and Ministry of Defence (MinDef). His command appointment includes; Platoon Commander, Bravo Company, First Battalion Royal Brunei Land Force (1Bn RBLF); Second in Command, Bravo Company, 1Bn RBLF; Resource Officer, Combat Engineer Squadron, Support Battalion RBLF (CES Sp Bn RBLF) and Officer Commanding CES Sp Bn RBLF. As a pioneer in Chemical, Biological, Radiological Defence, he was also responsible in setting up the establishment of Chemical, Biological, Radiological and Explosive (CBRE) Defence Unit and assumed command of the unit as the first Officer Commanding on 1st January 2010. His staff tour includes appointments as Assistant Strategy Management Officer, Office of Strategy Management, MinDef; Staff Officer Grade 2 J3 (Land), Joint Force Headquaters (JFHQ); Staff Officer Grade 1 J5, JFHQ and Staff Officer Grade 1 Force Capability Development (Land), Directorate of Force Capability and Development (DFCD), MinDef. Lieutenant Colonel Haji Rony Zai assumed the appointment of Commanding Officer Support Battalion Royal Brunei Land Forces on 19th February 2018.
Lieutenant Colonel Haji Rony Zai has attended various military career courses locally and overseas throughout his service. Among the courses he attended were Royal Engineers Troop Commanders Course (U.K), Chemical, Biological, Radiological Defence Commanders' Course (Singapore), Company Tactics Course (Singapore), Advanced Infantry Officers' Course (Singapore) and Battalion Tactics Course (Singapore). In 2012, Lieutenant Colonel Haji Rony Zai attended the 43rd Command and Staff Course in Goh Keng Swee Command and Staff College, SAFTI Military Institute, Singapore.
Lieutenant Colonel Haji Rony Zai received a Bachelor of Engineering (Hons) in Civil Engineering from the University of Manchester, United Kingdom in 1999. In his spare time, he enjoyed doing adventurous activities like diving and mountain biking. Lieutenant Colonel Haji Rony Zai is happily married to Lieutenant Commander Norharirayati bte Yakub, RBN and they are blessed with two daughters and two sons.