Senior Java Software Engineer - Legacy Platform Modernization

About the role

A large-scale modernization program for a high-volume legacy platform is looking for a Senior Java Software Engineer. You will build Java and Spring Boot middleware that connects an existing C/C++ desktop application with PostgreSQL, preserving critical business logic while supporting a gradual migration. You will work closely with engineers and client stakeholders to design solutions, troubleshoot integrations and explain technical decisions.

Key responsibilities

• Design, develop and maintain production-grade Java and Spring Boot services.
• Build data-access and integration components using Spring JDBC, Hibernate and REST APIs.
• Analyze C/C++ code, message flows, function calls and dependencies to safely update integration points.
• Optimize PostgreSQL performance through query tuning, indexing, partitioning, connection-pool configuration and caching.
• Support incremental migrations using automated testing, monitoring, dual reads, result comparisons and rollback mechanisms.
• Deploy and operate services on Azure using CI/CD pipelines and Infrastructure as Code.
• Collaborate with technical teams and client stakeholders to review designs, resolve complex issues and communicate risks and trade-offs.

Required profile

• 8+ years of experience developing production applications with Java and Spring Boot.
• Working knowledge of C/C++, able to read existing code, trace dependencies and make targeted changes.
• Strong communication and problem-solving skills, including explaining technical decisions to technical and non-technical stakeholders.

Required skills

• Spring JDBC and/or Hibernate, including transaction management, database connectivity and connection-pool configuration.
• PostgreSQL or a comparable relational database, including query optimization and performance troubleshooting.
• REST API design and integration, and enterprise backend services.
• Azure, CI/CD, observability, automated testing and Infrastructure as Code.
• Caching and messaging technologies such as Redis, Caffeine and Kafka.

Preferred: experience modernizing legacy C/C++ applications, progressive migrations and dual reads, high-volume system optimization, RAG/LLM integrations, AWS or GCP exposure, and Angular or React. Start date ASAP; contract ends March 31, 2027 with a high possibility of extension, working in the CST time zone, at $38 USD per hour.