Core Java Developer / Lead

Centillion Infotech LLC; Sacramento (CA); Remote; USD 150,000 - 190,000; Full time

Job summary

Centillion Infotech LLC is seeking a skilled Core Java Developer to design, develop, test, and maintain high-performance Java applications. You will collaborate with cross-functional teams to deliver reliable software solutions and modernize core platforms.

The role requires extensive Java experience, strong OOP and design pattern knowledge, and hands-on API development with SQL/NoSQL databases. Expect a fast-paced Agile environment with emphasis on code quality.

Qualifications

• Bachelor's degree in CS, Eng, IT or related field.
• 10+ years of Java software development experience.
• Strong core Java, including: object-oriented programming, collections framework, exception handling, generics, multithreading and concurrency, I/O/NIO, streams and lambdas.
• Experience developing RESTful APIs and backend services.

Responsibilities

• Design, develop, and maintain Core Java applications.
• Write clean, efficient, reusable, and maintainable code.
• Build and consume RESTful web services and APIs.
• Develop multithreaded, high-performance applications.
• Collaborate with architects, QA, DevOps, product managers, and stakeholders.
• Participate in code reviews and CI/CD integration.

Skills

Core Java

Multithreading

Data structures

Design patterns

RESTful services

SQL / ORM

Unit testing

Agile/Scrum

Interpersonal skills

Education

Bachelor's degree in Computer Science or related field

Tools

Maven or Gradle

Git

JUnit / Mockito

Spring / Spring Boot

Docker

Kubernetes

Cloud platforms (AWS/Azure/GC)

JDBC / ORM

Job description

Job Description

• Location: N/A, California, Georgia, New York
• Duration: Long Term

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 programmingCollections frameworkException handlingGenericsMultithreading and concurrencyJava I/O and NIOStreams and lambda expressionsJava memory managementGarbage collectionExperience 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
  • Java SE
  • Object-oriented programming
  • Collections and generics
  • Multithreading and concurrency
  • Streams and lambda expressions
  • Exception handling
  • Java I/O and NIO
  • JVM architecture
  • Memory management and garbage collection
  • Serialization and reflection
  • Data structures and algorithms
• Backend Development
  • RESTful APIs
  • HTTP and JSON
  • JDBC
  • Spring and Spring Boot
  • Microservices
  • Authentication and authorization
  • Transaction management
  • Service integration
  • Flexible work from home options available.