Amit Kumar

Full Stack Developer with 3+ years of experience building scalable backend applications, payment platforms and REST APIs using Java, Spring Boot, Micronaut, Hibernate/JPA, MySQL, MongoDB, Kafka, Redis and Docker. Experienced in payment gateway integration, transaction processing, routing, merchant onboarding, refunds, settlements, risk management and API security. Improved transaction throughput by 25%, success rates by 20%, administrative efficiency by 30%, and supported 50+ merchant onboardings.

Strong in database optimization, caching, asynchronous processing, API resilience and production troubleshooting.

Java Software Developer at V Vang Solutions Pvt. Limited (2024-04 – 2026-02)

• Developed backend modules for a payment aggregator platform using Java, Spring Boot, REST APIs, MongoDB, MySQL, Hibernate/JPA and Redis.
• Integrated and optimized payment gateway/acquirer APIs with validation, authentication, timeout and retry handling, improving transaction throughput by 25%.
• Designed payment routing and currency-acquirer mapping based on merchant, payment method, currency and gateway availability, improving success rates by 20%.
• Built transaction workflows covering authorization, capture, failure, refund, settlement and reconciliation, including idempotency and status validation.
• Developed merchant onboarding/configuration for 50+ merchants, supporting multi-currency, payment methods, acquirers, MDR, surcharge and reseller mapping.
• Built role-based dashboards and APIs for transaction history, refunds, billing, GST and settlements, reducing administrative effort by 30%.
• Implemented bulk refunds, risk rules and fraud-detection workflows; contributed to chargeback reduction and PCI DSS-aligned secure processing.
• Improved performance using MySQL indexing, query optimization, pagination, Redis caching, Hibernate optimization and asynchronous processing; performed JMeter testing and production troubleshooting.

Software Developer at GlobalHunt India Pvt. Limited (2022-09 – 2024-02)

• Developed scalable backend applications using Java, Micronaut, REST APIs, MySQL, MongoDB, Elasticsearch and AWS S3.
• Built APIs for company, brand, service, industry and geographic data with hierarchical Country–State–City–Area–Pincode relationships.
• Implemented dynamic search, filtering and pagination; optimized MySQL queries using indexing and efficient data-access patterns.
• Integrated MongoDB and Elasticsearch for flexible storage and high-performance search; implemented validation, exception handling and logging.
• Integrated APIs with Angular frontend and supported deployment automation, testing, production debugging and release activities.

B.Tech in Electrical & Electronics Engineering – JSS Academy Of Technical Education (2018-08 – 2022-06)