Udemy Refund System Rewrite

KotlinSpring BootArrowKTAWSKafka

Closeup of red berries

Overview

Led the rewrite of Udemy’s Refund System from the ground up using Kotlin and Spring Boot, with a focus on correctness and reliability in the B2C payment flow.

Approach

  • Used ArrowKT to implement a purely functional codebase with comprehensive error handling — eliminating unhandled exceptions entirely.
  • Designed for the complexities of synchronous and asynchronous communication between payment microservices.

Outcomes

  • More seamless refund experience for Udemy B2C customers.
  • Chargeback rates reduced by up to 3%.

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