Temporary Java Developers Jobs in Kearny, NJ (NOW HIRING)

Calling all innovators - find your future at Fiserv.

We're Fiserv, a global leader in Fintech and payments, and we move money and information in a way that moves the world. We connect financial institutions, corporations, merchants and consumers to one another millions of times a day - quickly, reliably, and securely. Any time you swipe your credit card, pay through a mobile app, or withdraw money from the bank, we're involved. If you want to make an impact on a global scale, come make a difference at Fiserv.

Job Title

About your role:

As a 10x Java Developer/AI Engineeryou will be an elite software builder who delivers high-scale, enterprise-ready systems at exceptional speed. This role is for a highly productive engineer who multiplies their individual output by integrating advanced Generative AI and Large Language Model (LLM) developer tools into their daily workflow. Far beyond writing standard application code, this builder builds production-grade Minimum Viable Products (MVPs), designs intelligent agentic workflows, and architectures scalable backend software that leverages LLMs directly to solve complex business problems.

You will have a proven track record of shipping actual production-scale products, moving rapidly past localized sandboxes or basic code prototypes, as well as an exceptional builder mindset focused on hyper-efficiency, continuous tooling experimentation, and engineering velocity.

What you'll do:

• High-Velocity MVP Delivery:Move rapidly from design concepts to writing production-ready code. Ship fully realized, resilient enterprise applications with speed and autonomy.
• AI-Assisted Engineering:Seamlessly embed GenAI assistants into daily workflows to drastically accelerate code writing, refactoring, test generation, and deep debugging.
• LLM & AI Application Building:Design, implement, and deploy application layers that integrate LLMs, retrieval-augmented generation (RAG) pipelines, and intelligent agentic workflows.
• Enterprise Java Engineering:Architect and write clean, maintainable, and high-performance Java code capable of processing concurrent, enterprise-scale workloads.
• CI/CD & Cloud Automation:Build and manage automated pipelines to package, test, and deploy applications continuously to cloud ecosystems.
• Architecture & Database Integration:Model secure, low-latency relational and non-relational database layers optimized for rapid application execution.
• Performance Tuning & Diagnostics:Conduct deep-dive profiling, memory leak detection, and technical troubleshooting on high-throughput backend services.

Experience you'll need to have:

• 8-10+ years in professional software engineering, with a strong focus on core backend Java platforms.
• Execution:A proven track record of shipping actual production-scale products, moving rapidly past localized sandboxes or basic code prototypes.
• Automation & Testing:Expert proficiency in writing automated unit, integration, and performance tests (e.g., JUnit, Mockito, Testcontainers).
• Mindset:An exceptional builder mindset focused on hyper-efficiency, continuous tooling experimentation, and engineering velocity.
• Advanced, hands-on engineering using Java 17+ or Java 21+ features (e.g., Virtual Threads, Pattern Matching).
• Deep expertise with Spring Boot, Quarkus, or Micronaut frameworks for building cloud-native microservices.
• Developer Velocity:Demonstrated mastery using GenAI developer assistants (e.g., GitHub Copilot, Claude Code, etc.) to achieve "10x" development, documentation, and unit test coverage.
• LLM Engineering:Hands-on integration with LLM APIs (OpenAI, Anthropic, or Amazon Bedrock) and vector databases.
• AI Frameworks:Building RAG and agent patterns using orchestration toolkits like Spring AI.
• Data Layers:Practical experience with PostgreSQL, NoSQL stores, and connection optimization.
• Streaming/Messaging:Experience with high-throughput message brokers like Apache Kafka or AWS SQS/SNS.
• Deployment:Familiarity with Docker, Kubernetes, and major cloud environments preferably AWS.
• Bachelor's degree in Computer Science, Information Technology, Information Systems, or a related field (or equivalent industry experience).

Experience that would be great to have:

• Experience in fintech/payments domains.

Important information about this role:

• This role is on-site Monday through Friday. Fiserv considers in-person collaboration to be an essential part of this role as in-person office experiences help you with your overall onboarding experience and leads to stronger productivity.
• You must currently possess valid and unrestricted U.S. work authorization to be considered for this role. Individuals with temporary visas including, but not limited to, F-1 (OPT, CPT, STEM), H-1B, H-2, or TN, or any candidate requiring sponsorship, now or in the future, will not be considered for this role.
• This is a full-time, direct-hire position, and no contract options for unsolicited agency submissions will be considered.
• All offers of employment are contingent on standard background checks. Fiserv and certain of its affiliated companies are federal, state, and/or local government contractors. Should this position support a Federal Government contract, now or in the future, the successful candidate will be subject to a background check conducted by the U.S. Government to determine eligibility and suitability for federal contract employment for public trust or sensitive positions. Positions that support state and/or local contracts also may require additional background checks to determine eligibility and suitability.

#LI-MK1

Salary Range

These pay ranges apply to employees in New Jersey and New York. Pay ranges for employees in other states may differ.

It is unlawful to discriminate against a prospective employee due to the individual's status as a veteran.

Thank you for considering employment with Fiserv. Please:

• Apply using your legal name
• Complete the step-by-step profile and attach your resume (either is acceptable, both are preferable).

Our commitment to Equal Opportunity:

Fiserv is proud to be an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, national origin, gender, gender identity, sexual orientation, age, disability, protected veteran status, or any other category protected by law.

If you have a disability and require a reasonable accommodation in completing a job application or otherwise participating in the overall hiring process, please contactAskHR.US@fiserv.com. Please note our AskHR representatives do not have visibility to your application status. Current associates who require a workplace accommodation should refer to Fiserv's Disability Accommodation Policy for additional information.

Note to agencies:

Fiserv does not accept resume submissions from agencies outside of existing agreements.Please do not send resumes to Fiserv associates. Fiserv is not responsible for any fees associated with unsolicited resume submissions.

Warning about fake job posts:

Please be aware of fraudulent job postings that are not affiliated with Fiserv. Fraudulent job postings may be used by cyber criminals to target your personally identifiable information and/or to steal money or financial information. Any communications from a Fiserv representative will come from a legitimate Fiserv email address.