Jos de Jong is a passionate programmer and creator of Mathjs, JSONEditor, and other open source projects. He believes in building useful software that solves real problems for users. Juggling multiple projects can be challenging, but he maintains a routine to manage his time effectively. Dealing with community-driven issues requires balancing user needs with personal goals. For new developers entering the open source world, de Jong advises working on something they believe in and enjoying the process. Testing is crucial for ensuring software quality, and simple tools are preferred over complex ones. Building a supportive community involves being respectful and maintaining a constructive attitude. In his spare time, de Jong enjoys spending time with family and playing computer games.