Mod Jacmob was a Jagex Moderator. He is also the owner of 'RSBuddy', the client used by the majority of OldSchool RuneScape players since 2014, and formerly a RuneScape bot. Mod MMG recruited Jacmob after the Bot Nuke in November 2011 as a Game Engine Developer and advisor to the executive team. From 2012-2014 Jacmob worked closely with executives at Jagex, and left the company soon after Mod MMG's departure.
Work at Jagex
Jacmob began 'full-time' employment at Jagex whilst at school, and continued during his degree programme at the University of Cambridge. He would fit in his work when he had time around his degree, but had some involvement in almost every Jagex product and service. He is best known for his work on the Bot Watch system from 2012-2014, and the internal procedures for its use. During his time overseeing Bot Watch, waves of bots were consistently banned from the game making sustained bot use infeasible.
The Old School team has mentioned that Jacmob was an important part of Old School's development, producing the internal map editor and other tools, as well as some significant game engine updates that were required for God Wars and other content. Jacmob made the engine changes necessary for resizable mode before his departure from the company.
Work after Jagex
Jacmob is still chief executive at the software company that runs RSBuddy and collaborates with the RuneScape team; however, he is working closely with Mod MMG and others that have left Jagex to work on new projects. As of April 2015, the nature of these projects has not been shared publicly.