First Warrant Officer Rosleen bin Hj Tujoh has served in Royal Brunei Land Force for 27 years which commenced on 02 May 1994. After undergoing his Basic Military Training at Training Institute RBAF on 11 Nov 1994, he was assigned to Third Battalion Royal Brunei Land Force. From 2000 until 2004, he was selected as a Recruit Instructor where he was awarded as Best Recruit Instructor twice before being posted back to his original unit as a Platoon Sergeant and awarded as best Platoon Sergeant in 2007.
In 2008, First Warrant Officer Rosleen was among those selected as Instructors when the Officer Cadet School was established. In May 2013, he took over duties as School Sergeant Major, Officer Cadet School and was promoted as Academy Sergeant Major, Defence Academy Royal Brunei Armed Forces in May 2018. After serving for 13 years at the Defence Academy Royal Brunei Armed Forces, First Warrant Officer Rosleen was entrusted to hold the position of Land Force Sergeant Major on 01 September 2021.
Throughout his career, he has undergone various courses both locally and internationally such as the Section Second In Command (2IC Sect) Course on 18 March 1996, Drill Instructor course on 27 June 1997, Section Commander on 5 September 1997, Weapons Instructor Course on 07 July 2000, Jungle Warfare Instructor(British TTB) on 27 July 2001, Combat Platoon Sergeant on 14 September 2001, GPMG Commander (Singapore) on 08 April 2004, Range Management Course (RMC) on 09 April 2008, Occupational Health And Safety for Senior Rank on 05 December 2012, Duty Watchkeeper on 12 December 2012, Assistant Unit Security Officer on 04 March 2013, Leadership and Management for Warrant Officers course in September 2014, Occupational Counsellors Course on 30 November 2015 and Group Crisis Intervention Course on 30 November 2020.
Among the courses he attended, he was awarded the overall Best Student award in the Sergeant Platoon Course, Small Arms Coaching Course, Major Sergeant Company Course and Warrant Officer Management and Leadership Course.
First Warrant Officer Rosleen has been awarded General Service Medal (GSM) in 1996, Armed Forces Golden Jubilee RBAF in 2011, Long Service Medal RBAF in 2012, Pingat Indah Kerja Baik (PIKB) in 2013, and The Most Blessed Order of Setia Negara Brunei (PSB) in 2016.
In his spare time, he enjoys playing badminton, jogging, hiking and reading books. He is married to Hjh Nurbadri binti Hj Md Nassir and has a daughter named Nurul Batrisyia Rosdeena.