Brainjockeys are cyberware hacker that use a special computer, a Braindeck, to find exploitable access point to hack people's cyberware.
Like Netrunners, they use a different system with their role ability. Brainjockeys use a system called "Brainjacking." When they are within 6m of a target, they can "decode" a target, allowing the brainjockey to hack that target's cyberware. The "hacking" takes the form of uploading programs which can have a variety of effects on the target.
Since brainjockeys can only decode a certain number of people at a time, they must choose who they hack wisely in combat. In addition, because they must be within 6 m/yds to upload programs, brainjockeys must learn to navigate the battlefield safely and must learn when to disrupt their targets.