Top Java Developer Jobs in St. Louis, MO

Develop and architect enterprise Java applications using Core Java, multithreading, Spring Boot microservices, REST APIs, Hibernate, and Oracle PL/SQL. Ensure security, high availability, and collaborate in Agile with global teams and business stakeholders.

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.

Lead reverse-engineering of TIBCO BW/MFT processes, document business rules, and reimplement them as modular Java/Spring Boot microservices. Migrate protocols to Kafka/RabbitMQ/REST, ensure data consistency, and perform performance testing to match legacy SLAs.

Lead architecture and delivery of large-scale microservices systems, define standards and roadmaps, mentor engineers, ensure scalability/resilience, oversee CI/CD, observability, data strategy, and cross-functional technical alignment.

Design, develop, and maintain high-performance Java microservices using Spring Boot. Implement threading/concurrency, fault-tolerance (Hystrix/circuit breakers), observability (SLI/SLO), and event-driven solutions with Kafka. Deploy and operate services on Kubernetes and AWS, mentor junior developers, and collaborate with cross-functional teams to deliver reliable, scalable features.

Design, implement, and maintain Java-based applications to automate financial data reconciliation across relational and NoSQL sources. Build deterministic and heuristic matching algorithms, integrate with rules engines (Drools), handle errors and exceptions, collaborate with analysts and architects to resolve data gaps, and support data governance and quality initiatives.

Design and build Java/J2EE solutions using Spring and APIs; develop webservices, DB schemas, PL/SQL and transactional SQL in DB2/Oracle; collaborate with architects, developers and DevOps to implement CI/CD (Jenkins, uDeploy), ensure code quality (Sonar), perform code reviews and testing, resolve technical roadblocks, and drive process improvements. Requires strong communication and teamwork.

Lead design and delivery of microservices-based backend systems, define architecture and standards, mentor engineers, drive cloud-native CI/CD and observability, ensure scalability, resilience, data strategy, and align technical solutions with business goals.

Design, implement, and maintain Java-based applications to automate complex data reconciliation across relational and NoSQL sources. Build matching algorithms, integrate with rules engines (Drools), handle data streams, perform gap analysis, and collaborate with analysts and architects to ensure data quality.

Lead software engineer responsible for designing, coding, testing, debugging, and stabilizing Java-based applications. Author and review technical designs, own complex stories and domain dependencies, mentor team members, enforce best practices, interact with business stakeholders, and improve processes and metrics. Provide guidance to contractors and participate in related agreements and SLAs.

Design, develop, and maintain scalable Java backend services and RESTful APIs. Collaborate with frontend, product, and stakeholders; write clean, tested code; troubleshoot and resolve issues; participate in code reviews; and improve systems, particularly for large-scale distributed environments.

Design, develop, and modernize software by translating legacy mainframe code (COBOL/ASM/JCL/Copybooks) into Java microservices. Support UI integration, relational and hierarchical databases, batch and real-time processing, CI/CD, cloud-native and ZT/ICAM integration, and use AI/ML tools to assist translation and optimization. Work supports pre-production, testing, and integration activities.

Develop and maintain Java Spring Boot microservices, write automated tests and API validations, debug and optimize performance, collaborate with architects, front-end developers and product owners, participate in Agile ceremonies, document designs, perform peer code reviews, and support deployments and release activities.

Design, develop, and maintain Java-based web applications and responsive frontends (Angular/React). Build and consume RESTful APIs and microservices, perform code reviews, mentor junior devs, collaborate with cross-functional teams, troubleshoot production issues, and ensure security, scalability, and reliability.

Develop and maintain core Elasticsearch infrastructure and shared platform features. Design scalable APIs, solve performance and concurrency issues, improve observability and CI/CD, automate developer workflows, lead cross-team projects, support complex operational investigations, and use AI to accelerate development and debugging.

Design, build, and improve Elasticsearch distributed-systems components for scalable, concurrent, and consistent indexing. Maintain cluster coordination for performance and resilience, push system scale limits, investigate performance and concurrency issues, support operations/support engineers, and lead projects involving multiple engineers from design through delivery.

The role involves improving Elasticsearch's distributed components, maintaining cluster coordination systems, and addressing complex issues to optimize performance and scalability.

Build, integrate, and stress-test full-stack applications and backend services that leverage advanced AI models. Develop production APIs, front-end features, databases, and cloud infrastructure; troubleshoot integrations; prototype rapidly and deliver high-quality code and documentation in fast-moving environments.

Develop and maintain Java applications for DoD systems, focusing on backend services, REST APIs, and microservices, while ensuring security and performance.

The Staff Engineer will leverage over 5 years of experience in Java, JavaScript, and frameworks to develop robust solutions, mentor teammates, and enhance client outcomes while utilizing agile methodologies and cloud development tools.

Seeking a Staff Engineer with 5+ years in Java, focusing on mentoring teammates, solving client challenges, and conducting cloud development.

Design, build, and maintain scalable, highly available backend services in Java. Own backend architecture, optimize performance, develop APIs and integrations, support production, conduct code reviews, and contribute to AI engineering tools and infrastructure.

Senior Java engineer responsible for designing, developing, and maintaining scalable, secure backend systems using Java and modern frameworks. Participate in architecture, collaborate with product and security teams, write maintainable code, and adopt AI-assisted development tools while contributing to open-source efforts.

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.

Senior individual-contributor backend engineer responsible for designing, building, and operating production-grade, highly available, strongly consistent services for wallet operations, transaction orchestration, blockchain integrations, and event-driven workflows. Implement secure, scalable APIs, cryptographic key management, Kafka-based event systems, observability with OpenTelemetry, CI/CD pipelines, and produce tests, API specs, and operational runbooks.