The following are some of the responsibilities a Java Developer:
Design, implement & maintain Java application phases
Taking part in architectural & software development activities
Conduct software analysis, testing, programming & debugging
Identifying production & non-production application issues
To transform requirements into stipulations
Develop, test, implement & maintain application software
Recommending changes to advance established Java application processes
Develop technical designs for app development
Develop app code for Java programs
If you want to become a Java Developer, check out this Java Certification by Intellipaat.
Also, watch this video to understand the role and responsibilities of a Java developer: