As a newcomer, take a look around
If you already read about DBpedia and how it works, look around our org github repositories. The main repos are the Extraction Framework and DBpedia Spotlight but there are many other sub-projects. The main programming languages we use are Scala, Java & some Shell Scripting but we also have side-projects in other languages like python.
Look at the repo wiki pages & try to build some code. If the documentation is not good, ask for our help and help us improve it.
Take a look at the existing bugs on our issue trackers to have an idea of what is there to fix
Introduce yourself to our developer mailing lists (or gsoc if you are a gsoc student).
Tell us a bit about yourself, your interests, what you like about DBpedia and the DBpedia (sub)projects you would like to work on (if you found one already) or ask us to help you choose one.
If you are a GSoC student, we have a dedicated page with available projects you can work on but we always welcome new ideas.
DBpedia covers a very big range of areas one can work on. Tell what you are interested in and we’ll try to best match your interests with our roadmap.