Senior Java Backend Engineer - POS & Payment Integrations

Ascendum System Private Limited; Cincinnati (OH); On-site; USD 115,000 - 140,000; Full time

Job summary

Ascendum System Private Limited is seeking an Advanced Software Engineer to join a team stabilizing a new system environment, integrating it with existing systems. The ideal candidate will have strong hands-on experience with Java, Spring/Spring Boot, backend services, API Gateway integrations, and enterprise payment systems, along with practical POS (point of sale) experience.

Experience working in PCI-scoped environments is highly valued.

Qualifications

• Proficient in Java and Spring ecosystem for backend services.
• Experience with API Gateway integrations and microservices architecture.
• Familiar with PCI-compliant secure development practices.

Responsibilities

• Design, develop, and maintain backend services using Java and Spring Boot.
• Support integration of the new POS platform with the current system.
• Develop and support integrations with enterprise API Gateway platforms and downstream services.
• Troubleshoot POS-to-backend and payment processing integrations.
• Perform hands-on testing using physical POS terminals in the onsite lab.
• Develop secure, scalable, highly available backend services.
• Collaborate with POS, payment, architecture, QA, DevOps, and product teams to resolve issues.
• Participate in design reviews, code reviews, and architecture discussions.
• Develop automated unit and integration tests.
• Investigate complex production issues and drive resolution.
• Support event-driven architectures and messaging technologies as required.
• Help establish development and integration practices for the team.

Skills

Java

Spring

Spring Boot

REST APIs

API Gateway

Microservices

POS Integration

PCI/Secure Development Practices

Tools

Kafka

Event-Driven Architecture

CI/CD

Cloud

Containers

NoSQL

Job description

Ascendum System Private Limited is seeking an Advanced Software Engineer to join a team stabilizing a new system environment, integrating it with existing systems. The ideal candidate will have strong hands-on experience with Java, Spring/Spring Boot, backend services, API Gateway integrations, and enterprise payment systems, along with practical POS (point of sale) experience.

Experience working in PCI-scoped environments is highly valued.