We are looking for a strong Java Backend Developer with 3 to 5 years of experience in developing scalable, secure, and high-performance backend applications.

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

The role involves developing and maintaining backend APIs for UPI and BBPS applications, including payment processing, transaction management, financial integrations, validations, reconciliation, and production support.

Key Responsibilities

- Develop and maintain backend services using Core Java and Spring Boot.
- Build and maintain REST APIs and Microservices for UPI and BBPS applications.
- Develop backend APIs for live UPI applications.
- Implement UPI transaction flows including:

- Payment initiation

- Transaction validation
- Success / Failed / Pending handling

- Transaction status enquiry

- Reversal and refund

- Callback / webhook processing

- Retry and exception handling
- 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 transaction management, idempotency, duplicate prevention, timeout and retry mechanisms.
- Develop business validations, transaction rules, audit logs, and reconciliation processes.
- Work with MySQL, PostgreSQL, or Oracle and write optimized SQL queries.
- Troubleshoot production issues, perform RCA,



and implement permanent fixes.
- Ensure API security, logging, monitoring, auditability, and data protection.
- Participate in code reviews, unit/integration testing, performance optimization, and production releases.

Mandatory Technical Skills
- Strong Core Java
- Java 8+
- Spring Boot / Spring MVC
- RESTful API development
- Microservices architecture
- Hibernate / JPA
- SQL and relational databases
- Exception handling and logging
- Git
- Maven / Gradle
- JUnit / Mockito
- Postman / API troubleshooting
- Third-party API integrations

Mandatory Domain Experience
- Hands-on experience with at least one live UPI application/UPI app
- Understanding of the UPI transaction lifecycle
- Experience with payment APIs and financial integrations
- Understanding of transaction states, reversals, refunds, retries, and reconciliation
- BBPS experience preferred
- Banking / FinTech / digital payments experience preferred

Valuable to Have
- Kafka / RabbitMQ
- Redis
- Docker / Kubernetes
- AWS / Cloud
- CI/CD
- Prometheus / Grafana / ELK
- High-volume transaction processing

Ideal Candidate The ideal candidate should be a strong Java Backend Engineer with hands-on UPI application experience, capable of independently developing APIs, implementing payment transaction logic, integrating external financial systems, and troubleshooting production payment issues. Key Requirement: Strong Java expertise + hands-on live UPI application experience is mandatory. BBPS / FinTech / Banking experience is preferred.

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