Senior Java Developer – Spring Boot, Microservices & Multithreading (W2 ONLY)

Location: Englewood Cliffs NJ
Duration: Long-Term Ongoing Contract
Experience: 8 Years
Position Type: Contract
Work Arrangement:Hybrid - 3 days a week onsite

We are seeking a highly skilled Senior Java Developer to join the engineering team of a leading media and technology organization.

The ideal candidate will have deep expertise in Core Java Spring Boot microservices architecture multithreading and high-performance backend application development.

This role involves designing developing and optimizing scalable reliable and high-throughput backend services supporting complex data-intensive enterprise applications.

We are looking for a technically strong hands-on engineer who understands Java internals concurrent programming distributed systems and production-level performance optimization.

• Design develop and maintain high-performance backend applications using Java and Spring Boot.

• Build scalable resilient microservices and RESTful APIs.

• Develop and optimize multithreaded and concurrent Java applications.

• Implement efficient asynchronous processing and parallel execution mechanisms.

• Design backend services capable of processing large volumes of data with low latency and high throughput.

• Apply distributed systems principles to ensure application scalability reliability and fault tolerance.

• Optimize application performance memory utilization JVM behavior and database interactions.

• Troubleshoot complex production issues involving concurrency thread contention memory leaks and performance bottlenecks.

• Collaborate with architects engineering teams and business stakeholders to translate requirements into robust technical solutions.

• Participate in architecture discussions technical design reviews and code reviews.

• Write clean maintainable well-tested production-quality code.

Core Java & Concurrency

• 8 years of professional Java development experience.

• Strong hands-on experience with Java 11/17/21 or newer.

• Excellent understanding of Java collections generics streams and functional programming.

• Deep knowledge of multithreading concurrency synchronization and thread safety.

• Experience with ExecutorService CompletableFuture thread pools concurrent collections and asynchronous programming.

• Strong understanding of JVM internals garbage collection memory management and performance tuning.

Spring Boot & Microservices

• Extensive hands-on experience with Spring Boot and the Spring ecosystem.

• Proven experience designing and developing microservices-based applications.

• Strong knowledge of REST APIs service-to-service communication and API design.

• Understanding of distributed transactions resilience patterns circuit breakers retries and fault tolerance.

• Experience building scalable highly available backend services.

Performance & Distributed Systems

• Experience developing high-throughput low-latency applications.

• Strong understanding of concurrent processing asynchronous workflows and event-driven architectures.

• Ability to identify and resolve performance bottlenecks.

• Experience with distributed caching messaging and data processing systems.

• Strong debugging profiling and production troubleshooting skills.

Databases & Development Tools

• Strong SQL skills and experience with relational databases such as PostgreSQL Oracle or MySQL.

• Experience with database query optimization and performance tuning.

• Proficiency with Git Maven/Gradle and automated testing frameworks.

• Experience with CI/CD pipelines and modern software engineering practices.

• Experience with market data financial data real-time data feeds or other data-intensive platforms.

• Hands-on experience with Kafka or similar event-streaming technologies.

• Experience with Redis or other distributed caching solutions.

• Familiarity with Kubernetes Docker and cloud platforms such as AWS.

• Experience with reactive programming frameworks.

• Understanding of messaging systems event processing and data ingestion pipelines.

• Experience building systems requiring high availability low latency and continuous data processing.

This is a hands-on senior engineering position not primarily a team management or coordination role.

The successful candidate should be comfortable:

• Writing complex Java code independently.

• Designing and troubleshooting multithreaded applications.

• Explaining concurrency concepts and their practical implementation.

• Building production-grade Spring Boot microservices.

• Solving complex performance and scalability challenges.

• Understanding architectural trade-offs in distributed systems.

• Taking technical ownership of backend components from design through production.

Candidates with strong Core Java fundamentals practical multithreading experience and deep Spring Boot/microservices expertise will be prioritized.

Required Skills:

JavaSpring BootMicroservicesThreadsCore Java