Top Senior Java Developer Jobs in Portland, ME

Design, build, and maintain efficient, reusable Java backend systems; translate business requirements into applications; optimize performance and stability; review and test code for quality and security; identify and fix bottlenecks and bugs; maintain code quality and system responsiveness.

Design, develop, test, and deploy full-stack Java applications (backend Java/Spring Boot, frontend React/Angular, PostgreSQL). Lead architecture decisions, mentor developers, perform code reviews, troubleshoot issues, implement testing strategies (JUnit, Cypress, Playwright), collaborate with product/QA/DevOps in Agile, and support VA mission-critical initiatives while meeting security and clearance requirements.

Design, develop, and maintain high-performance, secure Java backend services and APIs. Ensure reliability, scalability, and cost-efficiency across microservices, databases, messaging systems, and capacity planning. Troubleshoot, profile, benchmark, and optimize systems (including ML applications) and collaborate with Kazakhstan stakeholders.

Reverse-engineer TIBCO BW/MFT processes to extract business logic, then design and implement a modular Java/Spring Boot microservices replacement. Migrate protocols to Kafka/RabbitMQ/REST, translate XML transformations, ensure data persistence and consistency, and validate performance to meet existing SLAs.

Design, build, and maintain Java/J2EE multi-layer applications and APIs. Collaborate with architects and DevOps to implement CI/CD, code quality, testing, and database solutions (DB2/Oracle, PL/SQL). Support cross-team delivery, resolve technical roadblocks, and drive process improvements in an asset management/financial services context.

Analyze legacy TIBCO BusinessWorks/MFT processes to extract business logic, design and build a decoupled Java/Spring Boot microservices platform, migrate protocols to Kafka/RabbitMQ/REST, translate XML-heavy transformations to modern formats, and validate performance and SLAs to match legacy throughput.

The Senior Full Stack Java Developer will design and maintain enterprise applications using Java and modern front-end technologies while collaborating in Agile teams and mentoring junior developers.

As a Senior Software Engineer, you will maintain and develop data connectors, enhance data integrations, and improve developer experience within the ClickHouse data ecosystem.

Lead migration of legacy COBOL systems to Java-based microservices and develop scalable, secure full-stack solutions on Azure. Build RESTful APIs, optimize performance, ensure DoD cybersecurity compliance, collaborate across teams, document architectures, and participate in Agile ceremonies.

Join a small team to design and deliver high-quality, low-maintenance Java applications. Coach client teams on modern development practices, apply test-driven development, and pursue ongoing professional growth through training and mentorship.

The Senior Java Developer will design, develop, and implement custom software solutions in Agile teams, mentor juniors, and ensure product quality.

Architect, implement, and optimize live and on-demand streaming pipelines in Wowza. Design scalable transcoding and packaging workflows, debug performance issues, integrate native code via JNI, and serve as a streaming subject-matter expert across cross-functional projects.

Optimize and scale blockchain node performance, design and implement core system plugins, collaborate with cross-functional teams, conduct performance testing and debugging, and stay current on blockchain and distributed systems technologies to maintain reliable infrastructure.

Develop and maintain Java backend services for enterprise blockchain applications, integrate APIs with React/Vue frontends, design scalable blockchain solutions, troubleshoot complex backend issues, and collaborate with the team to apply best practices and stay current with blockchain trends.

The Senior Software Engineer will develop and maintain big data applications, focusing on distributed computing, automation, and collaboration with teams to enhance healthcare solutions.

As a Senior Software Engineer, you will build cloud solutions, define migration strategies, mentor junior engineers, and ensure architectural integrity while collaborating with peers.

As a Senior Developer, you will modernize COBOL systems to Java, enhancing functionality and performance while collaborating with stakeholders and ensuring coding standards are met.

Lead design and delivery of the WEX Bill Pay platform services. Define architectural roadmap, drive implementation and reuse across teams, champion testing/automation, ensure security and compliance, mentor engineering teams, and improve time-to-market through efficient engineering practices.

Lead backend architecture and implementation for Java Spring microservices, validate and own AI-assisted code, mentor engineers, collaborate with product to deliver features, and drive technical excellence and scalable, test-covered systems.

Design, develop, and maintain web-based UI and REST middleware for federal health IT systems. Participate in Agile/SAFe ceremonies, write design documents, implement features, resolve bugs, and support CI/CD pipelines while collaborating with product, QA, and stakeholders.

Develop, test, and maintain a complex distributed processing application using Python and Java. Collaborate with product owners, data coaches, analysts, DBAs, and Agile teams to meet backend/frontend requirements. Work with distributed workloads (Spark/Hadoop), SQL/Snowflake, AWS, shell scripting, and job scheduling/process automation. Support delivery under Agile/SAFe practices and ensure alignment with program standards.

Lead Software Engineer responsible for designing, developing, testing, and maintaining a distributed processing application using Python and Java. Collaborate with product owners, data coaches, analysts, DBAs, and Agile teams to meet backend/frontend requirements, implement cloud and big-data solutions (Spark/Hadoop), and ensure program standards and reliable delivery.

The Senior Java Engineer will design complex systems, optimize performance, maintain code quality, and ensure application reliability. Responsibilities include translating requirements into applications and troubleshooting issues.

Design, implement, test, and maintain full‑stack features and services for the Cayuse Research Platform. Drive architecture, prototypes, and technical debt reduction while practicing TDD, expanding automated QA, collaborating cross‑functionally, and ensuring high quality delivery in an Agile environment.

The Senior Software Engineer at Ensono will design, develop, and maintain enterprise Java applications, handle technical analyses, manage middleware configurations, and implement DevOps practices.