Java Payments Engineer – Spring Boot

SLEM Technologies; United States; Remote; USD 90,000 - 150,000; Full time

Job summary

SLEM Technologies is seeking a Java engineer to build and maintain services for our payment products. You will work with Spring Boot and integrate MPGS and Visa Cybersource to support checkout, processing, refunds, and reconciliation, while investigating failures and ensuring data security.

You will implement endpoints, handle 3-D Secure flows, manage notifications, write SQL, and contribute tests to verify handling of approvals, declines, and errors.

Qualifications

• 2+ years of professional Java experience, preferably in fintech or payment-processing systems.
• Hands-on integration experience with MPGS and Visa Cybersource.
• Practical experience with Spring Boot and relational databases.
• Understanding of authorisation, capture, refunds, tokenisation, 3-D Secure, and reconciliation.

Responsibilities

• Implement payment endpoints and gateway integration features in Java and Spring Boot.
• Maintain authorisation, capture, void, refund, tokenisation, and 3-D Secure flows with guidance from senior engineers.
• Process gateway notifications and payment statuses; use idempotency and safe retries to avoid duplicates.
• Write SQL queries and persistence code for transaction records and settlement reconciliation.
• Add unit and integration tests for approvals, declines, timeouts, and gateway errors.
• Investigate payment defects using sanitised logs and follow secure development practices.

Skills

Java

Spring Boot

Fintech/payments

HTTP APIs

Git and tests

Tools

SQL

Docker

CI/CD

Job description

SLEM Technologies is seeking a Java engineer to build and maintain services for our payment products. You will work with Spring Boot and integrate MPGS and Visa Cybersource to support checkout, processing, refunds, and reconciliation, while investigating failures and ensuring data security.

You will implement endpoints, handle 3-D Secure flows, manage notifications, write SQL, and contribute tests to verify handling of approvals, declines, and errors.