Ranjan Kumar Singh

Haldia Institute of Technology

B.Tech · Electronics and Communication Engineering

N/A – June 30, 2022

Nextbrain Technologies

Java Backend Developer

July 1, 2022 – Present

Vosita – Digital Healthcare Platform

April 29, 2026 – Present

Built a scalable healthcare platform for doctor appointment booking, patient management, and real-time notifications using microservices architecture with high availability, fault tolerance, and performance optimization. • Delivered end-to-end healthcare features including appointment scheduling, patient lifecycle tracking, and notification workflows in a microservices system. • Handled asynchronous healthcare workflows using Kafka-based event processing to ensure reliable scheduling and notification delivery. • Enhanced application performance by 30% and reduced database load by 40% through Redis caching, SQL tuning, and indexing strategies. • Secured REST APIs using Spring Security with JWT-based authentication and role-based access control (RBAC) to protect sensitive user data and ensure secure communication. • Deployed containerized applications using Docker on AWS (EC2, S3), implemented CI/CD pipelines using Jenkins, and performed API testing and validation using Postman.

GXS Bank – Digital Banking Platform

April 29, 2026 – Present

Developed a secure digital banking platform supporting account management, payments (UPI, IMPS, NEFT), and loan processing using microservices architecture with scalability, reliability, and compliance. • Led development of banking workflows for account management, payment processing, and loan lifecycle within a distributed system. • Applied Kafka-based event processing with Saga and Outbox patterns to ensure data consistency across financial transactions. • Designed and configured API Gateway using Spring Cloud Gateway with JWT authentication, rate limiting, request routing, and role-based access control (RBAC). • Enhanced transaction reliability and system stability using Redis caching, distributed locking, and circuit breaker patterns (Resilience4j) under high-load scenarios. • Enhanced MySQL performance using indexing, query tuning, and efficient schema design, and managed deployments on Kubernetes (AWS EKS) with CI/CD pipelines.