Entry Level Java Back End Developer Jobs in Belleville, NJ

Location: EU-Based, fully remote |Type: Contract B2B

We’re looking for a Back-End Engineer to design, build, and operate the services that power Elisity’s microsegmentation platform. You’ll work across our core backend -Java services, Kafka-based event streaming, and PostgreSQL data stores -building reliable, scalable systems that turn device intelligence and flow data into real-time policy decisions. This is a hands-on engineering role focused on system design, data correctness, and production reliability.

What you’ll do

• Design and build backend services in Java that ingest, process, and serve device-identity and network-flow data at scale.
• Own event-driven pipelines on Kafka -model topics, partitioning, ordering, and delivery guarantees so data flows reliably between services.
• Design and evolve PostgreSQL schemas for high-throughput, query-heavy workloads, and tune for performance, correctness, and safe migrations.
• Build and maintain APIs that other services and the product surface consume, with clear contracts and versioning.
• Make services production-ready: instrumentation, metrics, alerting, and the SLOs you’ll stand behind.
• Diagnose and resolve performance, scaling, and reliability issues across the data plane.
• Partner with architects, product owners, and other engineers to turn feature intent into well-scoped, buildable work.
• Contribute to code review, technical design discussions, and engineering standards.

What We’re Looking For

• Strong backend engineering experience building production services in Java.
• Hands-on experience with Kafka (or comparable streaming/messaging systems) - you understand topics, partitions, consumer groups, and delivery semantics.
• Solid PostgreSQL skills -schema design, indexing, query optimization, and safe migrations under load.
• A track record of building scalable, reliable distributed systems and reasoning about failure modes.
• Comfort owning services end to end, including observability and on-call-grade reliability.
• Clear communication and the ability to collaborate across a remote engineering team.

Nice to Have

• Experience in network security, device identity, or microsegmentation — or an adjacent security/networking domain.
• Experience with cloud-delivered, multi-tenant SaaS platforms.
• Familiarity with analytics or data-plane workloads, and large-scale data processing.

Why You’ll Love Working Here

• 100% remote with flexibility and trust.
• High-impact role in a fast-growing scaleup environment.
• Modern, cutting-edge tech stack with real room to experiment.
• Strong ownership and influence over backend and system-design decisions.
• Supportive, collaborative team that values learning and initiative.

Elisity is an identity-based microsegmentation company that helps enterprises stop lateral movement and contain breaches across IT, OT, and IoT environments. The Elisity platform discovers every device on an organization’s network, enforces least-privilege access policies through existing network infrastructure, and delivers full microsegmentation in weeks — without agents, additional hardware, or network re-architecture. Elisity is trusted by Fortune 500 healthcare systems, global manufacturers, and pharmaceutical companies including GSK, Main Line Health, Shaw Floors, and St. Luke’s University Health Network. Founded in 2019, Elisity has a global employee footprint and a growing number of customers in the Fortune 500, and has achieved many awards, including Gartner Cool Vendor (2025), SINIT16 Innovator (2025), and Forrester Strong Performer (2024).

Full Stack AI Engineer

Location: EU-Based, fully remote |Type: Contract B2B

We\u2019re looking for an engineer who combines solid full-stack fundamentals with fluency in modern AI tooling. You\u2019ll own features end-to-end — from backend services through integrations to polished UI — using agentic developer tools to dramatically accelerate delivery and quality.

What You\u2019ll Do

• Design and ship full-stack features: Java services on the backend, Kafka for event streaming, Postgres for data, React on the frontend, Playwright for QA.
• Use Claude Code (and similar agents) to automate your daily dev workflow.
• Take ownership of functionality, monitoring and UX.
• Collaborate closely with product to ship iteratively and learn fast.

What We\u2019re Looking For

• Real, daily use of Claude Code (or comparable agentic tooling) as a core part of how you work.
• A sharp eye for UX and attention to detail on the frontend.
• A generalist mindset: you\u2019d rather own a feature across the whole stack than specialize in one layer.

Nice to Have

• A track record of automating away your own toil.
• Strong experience with Java (Spring Boot or equivalent) and React.
• Hands-on knowledge of Kafka and Postgres — data modeling, query tuning, event handling.

Why You\u2019ll Love Working Here

• 100% remote with flexibility and trust.
• High-impact role in a fast-growing scaleup environment.
• Modern, cutting-edge tech stack with real room to experiment.
• Strong ownership and influence over frontend decisions.
• Supportive, collaborative team that values learning and initiative.

Elisity is a leap forward in network segmentation architecture and is leading the enterprise effort to achieve Zero Trust maturity, proactively prevent security risks, and reduce network complexity. The Elisity platform discovers every device on an organization\u2019s network, enforces least-privilege access policies through existing network infrastructure, and delivers full microsegmentation in weeks — without agents, additional hardware, or network re-architecture. Elisity is trusted by Fortune 500 healthcare systems, global manufacturers, and pharmaceutical companies including GSK, Main Line Health, Shaw Floors, and St. Luke\u2019s University Health Network. Founded in 2019, Elisity has a global employee footprint and a growing number of customers in the Fortune 500.

QA Tester / Quality Assurance Engineer

Location: EU-Based, fully remote |Type: Contract B2B

We are looking for a detail-oriented QA Tester who embraces modern AI-powered tools to enhance testing efficiency and quality. The ideal candidate combines solid QA fundamentals with the ability to leverage generative AI tools and AI-powered testing platforms to accelerate test creation, improve coverage, and streamline workflows.

Responsibilities

• Design, write, and execute test cases for web applications
• Identify, document, and track defects through resolution
• Develop and maintain automated test scripts using modern frameworks
• Leverage AI tools to accelerate test case generation and automation scripting
• Use AI-assisted tools to generate test data, edge cases, and exploratory testing scenarios
• Collaborate with developers and product teams in an Agile environment
• Participate in code reviews and provide quality-focused feedback
• Continuously improve testing processes by adopting AI-driven methodologies

Required Skills & Qualifications

Core QA Skills

• Professional experience in software QA/testing roles
• Strong understanding of SDLC methodologies
• Experience with manual testing techniques
• Proficiency with bug tracking tools (Jira, TestRail, or similar)
• Experience with Python

AI-Enhanced Testing Skills

• Experience with Claude Code, Gemini CLI, Codex or similar AI coding assistants for:
• Building and maintaining automation frameworks
• Generating test scripts through natural language commands
• Refactoring and optimizing existing test code
• Debugging test failures with AI-assisted analysis
• Generating test cases from requirements or user stories
• Writing and optimizing automation scripts
• Creating test data sets and edge case scenarios
• Summarizing and improving bug reports and documentation
• Ability to write effective prompts to get quality AI-generated outputs
• Understanding of when to use AI assistance vs. human judgment in testing

Automation Skills

• Experience with UI automation (Playwright, Selenium)
• Familiarity with API testing tools
• Understanding of Page Object Model and other test design patterns
• Basic understanding of CI/CD pipelines (Jenkins, GitHub Actions, GitLab CI)

Preferred Qualifications

• Ability to delegate complex testing tasks like framework setup, test suite creation, and CI/CD integration
• Experience with Pydantic for data validation and test data models
• Experience with pytest and pytest plugins
• Knowledge of async testing patterns for Playwright
• Knowledge of performance testing tools (Locust)

What We Value

• Agentic testing mindset - Comfortable delegating coding tasks to AI while focusing on strategy and quality decisions
• Critical thinking - Ability to evaluate, refine, and validate AI-generated code and test outputs
• Continuous learning - Stays current with emerging AI testing tools and techniques
• Quality focus - Understands that AI enhances but doesn\u2019t replace human judgment

Elisity is a leap forward in network segmentation architecture and is leading the enterprise effort to achieve Zero Trust maturity, proactively prevent security risks, and reduce network complexity.

Escalation Support Engineer

Location: Krakow, Poland

Elisity is seeking a versatile Escalation Support Engineer based in the EU, preferably in Krakow, Poland. In this role, you\u2019ll collaborate closely with enterprise customers to troubleshoot and resolve issues, create technical documentation for internal and external audiences, and work with the Engineering team to enhance product supportability. We\u2019re looking for someone adaptable, eager to learn, and ready to take on various responsibilities to meet our growing needs.

Essential Duties and Responsibilities

• Provide support to global customers and assist pre-sales activities through phone, web sessions, chat, and email.
• Perform live troubleshooting in pre-sales, pre-production, and production environments.
• Conduct offline analysis and escalate support cases as needed.
• Maintain the Elisity knowledge base and contribute to the development of the customer portal.
• Assist with proactive monitoring of cloud infrastructure.

Qualifications

• Experience supporting enterprise software installations.
• Proficiency in troubleshooting Linux and Unix environments.
• Familiarity with managing network and firewall equipment.
• Experience supporting network security products.
• Experience working with cloud infrastructure (AWS, Kubernetes).
• Ability to multitask and adapt to various roles in a fast-paced startup environment.
• Excellent communication skills and the ability to collaborate across teams.
• A proactive attitude with a passion for learning new technologies and tackling challenges.
• Startup experience or a strong entrepreneurial mindset is a plus.

Elisity is a leading cybersecurity firm providing customers with an innovative, cloud-delivered microsegmentation solution. Our platform enhances threat detection, simplifies policy management, and streamlines operations, ensuring stronger, smarter network security for businesses. Elisity is backed by Two Bear Capital, AllegisCyber Capital, and Atlantic Bridge.

Location: United States, Remote

Elisity is looking for a versatile Software Support Engineer in Remote, United States, to join the startup team. In this dynamic role, you\u2019ll be responsible for managing and troubleshooting incoming issues from enterprise customers, producing documentation for internal and external use, and working closely with Engineering to improve our products supportability. The ideal candidate is adaptable, eager to learn, and ready to jump into various roles as needed to support our evolving needs.

Essential Duties and Responsibilities

• Support global customers and pre-sales activity, over the phone, through web sessions, and through chat and email.
• Live troubleshooting in pre-sales, pre-production, and production environments.
• Offline analysis and escalation of support cases.
• Maintenance of the Elisity knowledge base and assisting with the development of the customer portal.
• Assist with pro-active monitoring of cloud infrastructure.

Qualifications

• Previous experience in supporting Enterprise software installations.
• Experience in troubleshooting Linux, Unix installations.
• Experience in managing network and firewall equipment.
• Experience in supporting network security products.
• Experience in supporting Cloud infrastructure (AWS, Kubernetes).
• Ability to wear multiple hats and switch between roles as needed to support our startup\u2019s evolving needs.
• Excellent communication skills and the ability to collaborate effectively with cross-functional teams.
• Proactive mindset with a willingness to learn new technologies and tackle challenges.
• Startup experience or a strong entrepreneurial spirit is a plus.

Elisity is a leading cybersecurity firm providing customers with an innovative, cloud-delivered microsegmentation solution. Our platform enhances threat detection, simplifies policy management, and streamlines operations, ensuring stronger, smarter network security for businesses. Elisity is backed by Two Bear Capital, AllegisCyber Capital, and Atlantic Bridge.

Location: United States, Remote

Elisity is looking for a versatile Software Support Engineer in Remote, United States, to join the startup team. In this dynamic role, you\u2019ll be responsible for managing and troubleshooting incoming issues from enterprise customers, producing documentation for internal a