Jeffrey, with over 1K hours of coding tracked on WakaTime, is a proficient developer showing a strong focus in Java alongside significant experience in Groovy, Dart, Markdown, and XML. While his GitHub presence is modest with 8 followers, his dedication to coding across various languages including C++, JSON, C, YAML, HTML, and even Rust and TypeScript suggests a versatile skill set. His engagement with the developer community on StackOverflow also reflects an active involvement with 23 total reputation.