Job Summary

We are looking for a Java Backend Developer with 3 to 5 years of experience in developing scalable and secure backend applications for UPI, PPI and BBPS payment platforms.

The candidate must have hands-on production experience working on at least one live UPI application/UPI app. Strong experience in Core Java, Spring Boot, REST APIs, Microservices, SQL and third-party API integrations is required.

Key Responsibilities

- Develop backend services using Core Java and Spring Boot.
- Design and develop REST APIs and Microservices for UPI and BBPS applications.
- Develop and maintain backend APIs for live UPI applications.
- Implement UPI transaction flows including payment initiation, validation, success/failure/pending status, status enquiry, reversal, refund and callbacks/webhooks.
- Implement retry, timeout, exception handling and duplicate transaction prevention.
- Develop BBPS APIs for bill fetch, bill payment, transaction status, validation and reconciliation.
- Integrate with banks, PSPs, payment gateways, BBPS systems, billers and third-party APIs.
- Implement idempotency, transaction validation, business rules, audit logging and reconciliation.
- Work with MySQL, PostgreSQL or Oracle and write optimized SQL queries.
- Troubleshoot production issues and perform RCA.
- Implement API security, logging,



monitoring and secure data handling.
- Participate in code reviews, testing, performance optimization and production releases.

Mandatory Skills

- Core Java / Java 8+
- Spring Boot / Spring MVC
- REST API development
- Microservices
- Hibernate / JPA
- SQL MySQL / PostgreSQL / Oracle
- Git
- Maven / Gradle
- JUnit / Mockito
- Postman
- Third-party API integration
- Exception handling and logging

Mandatory Payment Domain Experience

- Hands-on experience with at least one live UPI application/UPI app
- Strong understanding of UPI transaction lifecycle
- Payment API and financial system integrations
- Transaction status, reversal, refund and retry handling
- Timeout and duplicate transaction handling
- Idempotency
- Reconciliation
- Production issue troubleshooting
- Banking / FinTech / Digital Payments experience

Valuable to Have

- BBPS
- PPI / Digital Wallet
- Kafka / RabbitMQ
- Redis
- Docker / Kubernetes
- AWS / Cloud
- CI/CD
- Prometheus / Grafana / ELK
- High-volume transaction processing

Contract Details

- 6-month Contract-to-Hire position
- Onsite work in Chennai
- Contract may be extended or converted to a permanent position based on project requirements and performance
- Candidates must be willing to work onsite in Chennai

📌 Java Backend Developer /UPI & BBPS (Chennai)
🏢 ThreatXIntel
📍 Chennai