Mr Koh is currently the Head of Engineering for the North East Line (NEL) and the Sengkang Punggol Light Rail Transit (SPLRT) operated by SBS Transit Rail Pte. Ltd. in Singapore. Prior to this appointment, he assumed the Head of Rolling Stock for both lines as well as Head of Signalling and Communications for SPLRT. Before joining SBS Transit Rail Pte. Ltd., he held various engineering and maintenance-related positions with the Republic of Singapore Air Force. Having more than 20 years of experience, he is an electrical and electronics engineer by training with a specialisation in communication and network systems.