Java Developer

About the role

Job Summary We are seeking an experienced Senior Core Java Developer with 10+ years of hands-on software development experience to design, develop, enhance, and maintain high-performance enterprise applications. The ideal candidate will have strong expertise in Core Java, Java/J2EE, multithreading, concurrency, collections, JVM, design patterns, and object-oriented programming. The candidate will work closely with architects, product managers, QA engineers, and other development teams to deliver scalable, reliable, and high-quality software solutions.Key Responsibilities

• Design, develop, test, and maintain enterprise applications using Core Java.

• Develop scalable and high-performance backend services and applications.

• Apply strong knowledge of Object-Oriented Programming (OOP), SOLID principles, and design patterns.

• Work extensively with Java Collections, Exception Handling, Multithreading, Concurrency, Generics, Streams, and Lambda expressions.

• Analyze application performance and troubleshoot complex production issues.

• Perform JVM tuning, memory analysis, garbage collection analysis, and performance optimization.

• Design and implement reusable, maintainable, and testable software components.

• Develop and integrate RESTful APIs and web services.

• Work with relational and NoSQL databases and optimize SQL queries when required.

• Participate in application architecture and technical design discussions.

• Conduct code reviews and provide technical guidance to junior and mid-level developers.

• Collaborate with QA teams to develop unit, integration, and automated tests.

• Identify technical risks and recommend appropriate solutions.

• Troubleshoot defects and production issues and provide root-cause analysis.

• Contribute to CI/CD, automated build, deployment, and DevOps processes.

• Ensure applications follow security, coding, performance, and development best practices.

• Prepare technical documentation and contribute to engineering standards. Required Skills

• 10+ years of professional Java development experience

• Strong expertise in Core Java

• Strong understanding of:

• Java Collections Framework

• Multithreading & Concurrency

• Exception Handling

• Generics

• Java Streams

• Lambda Expressions

• Java Memory Management

• JVM Architecture

• Garbage Collection

• Serialization

• Strong knowledge of Object-Oriented Design and Design Patterns

• Experience with Java 8+, preferably Java 11/17/21

• Strong experience developing REST APIs / Web Services

• Experience with Spring / Spring Boot

• Strong SQL and relational database experience

• Experience with databases such as Oracle, PostgreSQL, MySQL, or SQL Server

• Experience with JUnit, Mockito, or other testing frameworks

• Experience with Git and source-control practices

• Experience with Maven or Gradle

• Understanding of CI/CD pipelines and DevOps practices

• Strong debugging and problem-solving skills Preferred Skills

• Experience with Microservices architecture

• Experience with Kafka, RabbitMQ, or other messaging platforms

• Experience with Docker and Kubernetes

• Cloud experience with AWS, Azure, or GCP

• Experience with distributed systems and high-volume applications

• Knowledge of caching technologies such as Redis

• Experience with application servers such as Tomcat, WebLogic, or JBoss

• Experience with performance monitoring and observability tools

• Knowledge of secure coding practices and application security Education Bachelor s or Master s degree in Computer Science, Information Technology, Engineering, or a related field, or equivalent professional experience.Key Technical Keywords Core Java, Java, Java 8+, Java 11, Java 17, Java 21, J2EE, OOP, Collections, Multithreading, Concurrency, JVM, Garbage Collection, Memory Management, Design Patterns, SOLID, Spring, Spring Boot, REST API, Microservices, SQL, Oracle, PostgreSQL, MySQL, JUnit, Mockito, Maven, Gradle, Git, Docker, Kubernetes, Kafka, AWS, Azure, GCP, CI/CD.

About technology at ApTask

Technology roles at ApTask cover the software, cloud, data, security, and platform-engineering functions that power Fortune 500 digital operations. Our recruiters specialise in high-signal technical calibration — every candidate is validated against the specific stack, framework versions, and deployment context the client runs, not a keyword match. Our largest engagements sit inside AWS, Azure, GCP, Snowflake, Databricks, and modern data-mesh estates. Because we route through Fieldglass, Beeline, Workday VNDLY, and Coupa VMS, technology contractors placed through ApTask carry MBE diversity spend against the client's supplier program while remaining W-2 with full benefits under our payroll.