The London MongoDB User Group, founded in March 2011, has grown to approximately 650 members and meets monthly at 10gen's office in Shoreditch. Running the group poses challenges such as finding speakers for each meetup, which requires a constant influx of new topics and ideas. To encourage growth, David Mytton uses his own promotional channels, connects with companies using MongoDB, and leverages 10gen's involvement to attract speakers. Outside of work, he has a passion for cycling, having recently completed a three-week trip in Japan. The group's next meetup is scheduled for August 28.