Senior Java Developer

Location: New Jersey (Onsite – Mandatory)

Duration: Contract through end of year (extension likely)

Client is looking for a Senior Java Backend Developer to support and enhance the First Net system
, a mission-critical platform used by first responders. This role focuses on backend Java development
, making enhancements and changes to existing systems rather than greenfield UI work.

The hiring manager is looking for a strong Java foundation and real-world enterprise experience. The role is 80% backend Java
, with minimal UI involvement.

• Enhance and maintain existing Java backend applications supporting the First Net platform
• Analyze and modify current systems to support new business and operational requirements
• Develop and support REST-based backend services
• Work closely with internal teams to implement system changes safely and efficiently
• Participate in code reviews, debugging, and production support
• Ensure code quality, performance, and reliability in a mission-critical environment

• 10+ years of hands-on Java development experience
• Strong core Java fundamentals (any stable version acceptable)
• Experience working on large-scale enterprise backend systems
• Strong understanding of object-oriented design and backend architecture
• Experience with RESTful services
• Solid experience with SQL and relational databases
• Ability to work with and enhance existing legacy systems
• Strong troubleshooting and debugging skills