Onsite_Principal Java Developer_Jersey City, NJ

THEMESOFT; Jersey City (NJ); On-site; USD 138,000 - 207,000; Full time

Job summary

Themesoft Inc in Jersey City, NJ is seeking a Principal Java Engineer to provide hands-on technical leadership for the design, development, and modernization of large-scale enterprise applications. You will mentor teams while shaping technical direction and architecture across services.

Onsite, contract role lasting 6 months with deep dive into Java, Spring Boot, microservices and cloud-native patterns. Strong collaboration with architects and product teams is required to drive modernization and

Qualifications

• 12+ years of software engineering experience with enterprise Java applications.
• Expert-level knowledge of Java/JDK, Spring Framework, Spring Boot and ecosystem.
• Strong experience with microservices and distributed systems.
• Deep understanding of REST APIs, design and event-driven patterns.
• Experience with Kafka or similar messaging platforms.
• Strong SQL databases experience (Oracle/PostgreSQL/SQL Server).
• Proficient with Docker and Kubernetes.
• Experience on Azure, AWS or another major cloud platform.
• Solid CI/CD, DevSecOps knowledge and tooling.
• Experience with JUnit/Mockito and integration testing.
• Security, observability, and production troubleshooting expertise.
• Demonstrated technical leadership and stakeholder management.

Responsibilities

• Provide technical leadership for Java, Spring Boot and microservices.
• Design scalable, secure, high-performing distributed systems.
• Hands-on architecture, reviews, and complex troubleshooting.
• Define engineering patterns, frameworks, and coding standards.
• Drive modernization and decomposition of monoliths.
• Design and integrate REST APIs and Kafka-based events.
• Lead API design, data models, caching, resiliency and observability.
• Work with Docker, Kubernetes and cloud platforms (Azure/AWS).
• Advance CI/CD, automated testing, security, performance and observability.
• Troubleshoot production issues across layers.
• Collaborate with architects, product owners and leads; mentor engineers.
• Evaluate new technologies and guide pragmatic adoption.

Skills

Java

Spring Boot

Microservices

REST APIs

Kafka

Docker

Kubernetes

Cloud Platforms

CI/CD

Security & Observability

Code Review & Troubleshooting

Leadership

Relational Databases

Tools

JUnit

Mockito

Maven

Gradle

GitHub Actions

Jenkins

Azure DevOps

OpenTelemetry

Job description

Job Id : OOJ - 27718

Posted Date : 10/21/2026

Experience : 15-30

Job Type : Contractual

Location : JERSEY CITY

Title: Principal Java Developer

Location: Jersey City, NJ(Onsite)

Work Arrangement: Onsite

Employment Type: Contract

Duration: 6 Months

Primary Skills: , Microservices, Java,Docker/Kubernetes

We are seeking a Principal Java Engineer to provide hands-on technical leadership for the design, development, and modernization of large-scale enterprise applications. The role requires deep expertise in Java, Spring Boot, microservices and cloud-native engineering, along with the ability to define technical direction, solve complex engineering challenges, and mentor development teams.

Key Responsibilities

• Provide technical leadership for enterprise applications built using Java, Spring Boot and microservices architecture.
• Design scalable, resilient, secure, and high-performing distributed systems.
• Remain hands-on with architecture, design and critical code development, including code reviews and complex troubleshooting.
• Define engineering patterns, reusable frameworks, coding standards, and development best practices.
• Drive application modernization, including decomposition of legacy/monolithic applications into modern services.
• Design and integrate REST APIs, event-driven services and asynchronous processing using technologies such as Kafka.
• Lead technical decisions around APIs, data models, caching, resiliency, observability, and integration patterns.
• Work with Docker, Kubernetes and cloud platforms such as Azure or AWS to develop and deploy cloud-native applications.
• Drive engineering excellence across CI/CD, automated testing, security, performance and observability.
• Troubleshoot complex production and performance issues across application, database, integration, and infrastructure layers.
• Partner with architects, product owners, business teams and engineering leads to translate business requirements into effective technical solutions.
• Mentor senior engineers and developers and provide technical guidance across multiple development squads.
• Evaluate emerging technologies and recommend pragmatic adoption based on business and engineering value.

Required Skills

• 12+ years of software engineering experience, with significant experience building enterprise Java applications.
• Expert-level knowledge of Java/JDK, Spring Framework, Spring Boot and Spring ecosystem.
• Strong experience with microservices and distributed systems architecture.
• Deep understanding of REST APIs, API design, integration patterns and event-driven architecture.
• Experience with Kafka or equivalent enterprise messaging/event-streaming platforms.
• Strong knowledge of relational databases such as Oracle, PostgreSQL or SQL Server; exposure to NoSQL platforms is desirable.
• Strong experience with Docker and Kubernetes.
• Experience developing applications on Azure, AWS or another major cloud platform.
• Strong understanding of CI/CD and DevSecOps, using platforms such as GitHub Actions, Jenkins, Azure DevOps, Maven or Gradle.
• Experience with automated testing frameworks including JUnit, Mockito and integration testing.
• Strong understanding of application security, authentication/authorization, resiliency, logging, monitoring and observability.
• Proven ability to perform code reviews, performance tuning, root-cause analysis and production troubleshooting.
• Strong technical leadership, communication and stakeholder-management skills.

Preferred Skills

• Experience with AKS/EKS, Terraform and infrastructure-as-code.
• Experience with Redis, MongoDB or other NoSQL technologies.
• Knowledge of OAuth 2.0, OIDC and enterprise IAM/security patterns.
• Experience with tools such as SonarQube, Dynatrace, Splunk, AppDynamics or OpenTelemetry.
• Experience modernizing complex legacy applications in banking, insurance or financial services.
• Exposure to Generative AI / AI-assisted software engineering and tools such as GitHub Copilot

Work Authorization

Applicants must be legally authorized to work in the United States.

Equal Employment Opportunity

Themesoft Inc is an Equal Employment Opportunity employer. We consider qualified applicants without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, veteran status, or any other status protected by applicable federal, state, or local law.

Skills :

GRADLE,MICROSERVICES ARCHITECTURE,AZURE,NOSQL,CI/CD,AUTOMATED TESTING,SPRING FRAMEWORK,DEEP EXPERTISE,DOCKER,KUBERNETES,AWS,REDIS,HANDS-ON TECHNICAL LEADERSHIP,SPRING BOOT,SQL SERVER,JAVA,POSTGRESQL,SPLUNK,MAVEN,JUNIT,MOCKITO