Sr. Core Java Developer / Lead

Iselin, NJ

Job Description:

About the Role

We are seeking a skilled Core Java Developer to design, develop, test, and maintain high-performance, scalable, and reliable Java applications.
The ideal candidate will have a strong foundation in core Java concepts, object-oriented programming, multithreading, data structures, design patterns, and enterprise application development.
The successful candidate will collaborate with architects, developers, QA engineers, DevOps teams, product managers, and business stakeholders to deliver high-quality software solutions.

Key Responsibilities

Design, develop, and maintain applications using Core Java.
Write clean, efficient, reusable, and maintainable code.
Apply object-oriented programming principles and software design patterns.
Develop multithreaded, concurrent, and high-performance applications.
Work with Java collections, exception handling, generics, streams, and lambda expressions.
Build and consume RESTful web services and APIs.
Develop modular and scalable application components.
Implement business logic, validation, error handling, and transaction management.
Work with relational and NoSQL databases.
Write efficient SQL queries and optimize database interactions.
Perform unit, integration, functional, and regression testing.
Troubleshoot application issues, memory leaks, performance bottlenecks, and production defects.
Participate in code reviews and ensure adherence to coding standards.
Collaborate with cross-functional teams to understand requirements and deliver solutions.
Contribute to technical design documents and implementation plans.
Integrate applications with CI/CD pipelines.
Support application deployment, monitoring, and production issue resolution.
Participate in Agile ceremonies, sprint planning, daily stand-ups, reviews, and retrospectives.
Stay current with Java releases, development practices, tools, and industry trends.

Required Qualifications

Bachelor’s degree in Computer Science, Engineering, Information Technology, or a related field.
10+ years of experience in Java software development.
Strong knowledge of Core Java, including:
Object-oriented programming
Collections framework
Exception handling
Generics
Multithreading and concurrency
Java I/O and NIO
Streams and lambda expressions
Java memory management
Garbage collection
Experience with Java 8 or later.
Strong understanding of data structures, algorithms, and design patterns.
Experience developing RESTful APIs and backend services.
Knowledge of relational databases such as Oracle, SQL Server, MySQL, or PostgreSQL.
Experience with SQL, JDBC, and ORM concepts.
Familiarity with Maven or Gradle.
Experience with Git or other version-control systems.
Understanding of unit testing using JUnit, Mockito, or equivalent tools.
Familiarity with Agile/Scrum development methodologies.
Strong analytical, debugging, communication, and problem-solving skills.

Preferred Qualifications

Experience with Java 11, 17, 21, or later.
Experience with Spring, Spring Boot, Spring MVC, Spring Data, or Spring Security.
Knowledge of microservices architecture.
Experience with messaging technologies such as Kafka, RabbitMQ, JMS, or ActiveMQ.
Familiarity with Docker and Kubernetes.
Experience with cloud platforms such as AWS, Azure, or Google Cloud.
Knowledge of CI/CD tools such as Jenkins, GitHub Actions, GitLab CI, or Azure DevOps.
Experience with NoSQL databases such as MongoDB, Redis, Cassandra, or DynamoDB.
Familiarity with distributed systems, caching, and event-driven architecture.
Experience with application monitoring and observability tools.
Knowledge of secure coding practices and application security.
Experience with performance testing and profiling tools.
Familiarity with Linux/Unix environments and shell scripting.

Technical Skills

Core Java

W2 - 10+ Java Developer / Lead for Iselin, NJ

Key skills