Reuben enlisted in the Singapore Armed Forces in 2013, where he graduated from Basic Military Training as Platoon Best Recruit and went on to Specialist Cadet School as a Sergeant-in-training. Earning the Silver Bayonet as a Distinguished Graduate 6 months later, he proceed with the Basic Warfighter Platoon Sergeant course and graduated 4 months later. He then went to the Guards Conversion Course in October 2014, earning his Khaki beret and Guards shoulder tab as a member of the Singapore Guards Formation, an elite infantry formation in the Singapore Armed Forces specializing in rapid deployment, heliborne and amphibious operations, maneuver warfare and urban combat. In 2015, he was went for the Reconnaissance, Surveillance and Target Acquisition (RSTA) Commander Course and served as a recce team commander from 2014- 2015. In 2016, he was appointed Platoon Sergeant of a temporary platoon during the Physical Training Phase for a batch of new recruits before being a Section Commander from 2016 - 2017. He was qualified as a Basic Combat Fitness Trainer as well as a lifeguard for the Singapore Armed Forces during his stint as a section commander. In 2018, he spent one year on secondment to the Soldier System Integration Lab (SSIL) branch of the Centre of Excellence for Soldier Performance (CESP) as a Field Trial Specialist and contributed to the project of a new load bearing vest for the Singapore Armed Forces, where he did a presentation to the then 2nd Minister of Defence, Dr Ong Ye Kung. In 2019, prior to leaving the Service, Reuben obtained certification as a personal trainer and a sports nutrition specialist. He started at Gold's Gym Singapore as a personal trainer and is currently under employment at Virgin Active as an Exercise Experience Coach.