A Java Optimization Developer focuses on improving the efficiency of Java applications. They analyze code for bottlenecks, identify areas for improvement, and implement modifications to enhance performance. They often use profiling tools to gather data on how programs run, including memory usage and execution speed. They also ensure that the code adheres to best practices for optimization, such as proper use of data structures and algorithms. Additionally, they may work on tuning the Java Virtual Machine (JVM) settings for optimal performance. They collaborate closely with other developers to ensure the application remains functional and efficient after optimization.