Formal education or certification is sometimes necessary for a Java developer, especially when you hire remote developers, but practical experience and demonstrated skills can be just as valuable. Certifications, such as the Oracle Certified Professional, can demonstrate a developer's proficiency in Java. Certifications can benefit those seeking to advance their career or specialize in a particular area of Java development. However, it's important to note that certification alone may not necessarily reflect a developer's ability to work on real-world projects.