Codebits is a hackathon style even organized by SAPO in Lisbon. I have played different roles in the event organization each year (I've even cooked!), but mainly, I've been the graphic designer responsible for the event's image.
One of my jobs was to design the t-shirts we give away each edition and which are always a huge success among the community. It's not unusual to see people around Lisbon wearing these and they were all great fun to create. The original green "bot" was created by Pedro Correia.
For each illustration, I started with a pencil sketch which I photographed into my computer and then recreated using Illustrator.