Do you need to know all design patterns (as a Java Developer)?

It is not necessary for a Java developer to know all design patterns. However, it is generally considered a good idea for a developer to be familiar with some of the most common design patterns, as they can be useful tools for solving common design problems that arise in software development. Knowing some design patterns can also make it easier for a developer to communicate with other members of a development team and understand code written by others. That being said, it is not necessary to know all design patterns to be a successful Java developer.