Sr API & Middleware Engineer (PM Express)

Job Description:
One our our to clients in the Aerospace & Defense Industry is seeking a Senior API & Middleware Engineer to support a strategic enterprise application used by Program Managers and business stakeholders for financial planning, forecasting, and program/portfolio-level financial management. This application is replacing traditionally manual, spreadsheet-heavy processes with a modern platform that brings together secure APIs, workflow automation, enterprise system integrations, financial and project data, background processing, analytics, and cloud-based technologies.

In this role, you will be a hands-on backend engineer responsible for designing and developing Spring Boot microservices, REST APIs, middleware integrations, data-access layers, and scheduled/background processing supporting new and existing application capabilities. You will also help ensure services are secure, scalable, production-ready, and successfully deployed within their AWS environment. This is a great opportunity for someone who enjoys owning backend solutions end to end and wants to make a significant impact on a highly visible enterprise platform at a Fortune 50 company!

Requirements:
• 7+ years of experience in Java/Spring-based application development, with strong recent hands-on experience in Spring Boot and enterprise middleware
o Strong integration experience with external enterprise systems, APIs and data sources
• Hands-on API and middleware engineering experience, including REST API design, versioning, validation, exception handling, OpenAPI/Swagger, and enterprise integration patterns
• Experience building scheduled/background processing and enterprise integrations, using tools such as JobRunr or Spring Batch
• Strong JPA/Hibernate and SQL/database experience, including data modeling, transactions, query optimization, performance troubleshooting, and relational databases such as PostgreSQL
• Hands-on experience with AWS, Docker, and CI/CD in cloud-based application environments (their services are deployed completed on AWS but data bricks and application registration exist on Azure)

Nice to have:
• Exposure to Databricks or other cloud data platforms for application/data integrations
• Experience supporting applications in regulated or security-focused environments

Responsibilities:
• Design, develop and maintain Spring Boot microservices and middleware APIs supporting the application business capabilities.
• Translate business and product requirements into scalable API contracts, domain models, persistence designs and integration workflows.
• Implement secure authentication and authorization patterns and ensure APIs meet enterprise security and compliance expectations.
• Develop and optimize JPA/Hibernate persistence logic and SQL queries; diagnose data, transaction, locking and performance issues.
• Build and support scheduled/background jobs, batch processes, automated notifications and data synchronization workflows.
• Integrate the application with enterprise data sources and platforms, including transactional systems, cloud data platforms and other internal services.
• Participate in code reviews, automated testing, CI/CD, security scanning, release activities, production troubleshooting and continuous technical improvement.
• Build, deploy, monitor, and troubleshoot Dockerized Spring Boot services running in AWS, collaborating with DevSecOps/platform teams on ECS/Fargate deployments, configuration, secrets, networking, logging, and application health.
• Participate in CI/CD and release processes, helping ensure services are securely packaged, scanned, deployed, monitored, and operationally ready across environments.