Senior Java Backend Engineer (Spring) — POS & Payments

VSG Business Solutions LLC; Blue Ash (OH); On-site; USD 100,000 - 130,000; Full time

Job summary

VSG Business Solutions LLC is seeking an Advanced Software Engineer to join our team working on the Omnichannel Payment Platform (OPP) and a new POS system. You will stabilize the POS environment and drive integration with OPP, using Java and Spring Boot to build robust backend services.

The role focuses on API Gateway integrations, enterprise payment systems, PCI-compliant development, and hands-on testing with POS hardware in an onsite lab to ensure reliability and performance.

Qualifications

• Senior-level experience developing enterprise Java applications.
• Strong hands-on experience with Java, Spring, and Spring Boot.
• Experience developing RESTful APIs and backend microservices.
• Experience with API Gateway integration and enterprise system integrations.
• Hands-on POS experience with POS terminals or test environments.
• Experience in PCI-scoped, payment, financial, or security-sensitive environments.
• Ability to work onsite with cross-functional technical teams.

Responsibilities

• Design, develop, and maintain backend services using Java and Spring Boot.
• Support the integration of the new POS platform with the Omnichannel Payment Platform (OPP).
• Develop and support integrations with enterprise API Gateway platforms and downstream services.
• Troubleshoot and stabilize POS-to-backend and payment processing integrations.
• Perform hands-on testing with physical POS terminals and test hardware in the onsite POS lab.
• Develop secure, scalable, and highly available backend services.
• Work within PCI-scoped environments, adhering to security standards.
• Collaborate with POS, payment, architecture, QA, DevOps, and product teams to resolve issues.
• Participate in technical design, code reviews, and architecture discussions.
• Develop automated unit and integration tests.
• Investigate complex integration and production issues.
• Support event-driven architectures and messaging technologies.
• Help establish development and integration practices for the OPP/POS team.

Skills

Java/Spring expertise

Backend development

REST APIs

API Gateway integrations

PCI/security compliance

POS integration experience

Onsite collaboration

Tools

Spring Boot

API Gateway platforms

Kafka

CI/CD

Cloud

Containers

POS testing hardware

Job description

VSG Business Solutions LLC is seeking an Advanced Software Engineer to join our team working on the Omnichannel Payment Platform (OPP) and a new POS system. You will stabilize the POS environment and drive integration with OPP, using Java and Spring Boot to build robust backend services.

The role focuses on API Gateway integrations, enterprise payment systems, PCI-compliant development, and hands-on testing with POS hardware in an onsite lab to ensure reliability and performance.