What happens when an e-commerce backend needs transactional consistency, flexible product data, asynchronous processing, and reliable audit logging—all at the same time?

A single database and tightly coupled services aren't always the best fit for every workload. While working on ShopEase , my full-stack e-commerce project, I worked on a backend architecture that separates storage responsibilities and decouples downstream processing using Apache Kafka.

This engineering work focuses on three areas:

Polyglot Persistence Architecture

CQRS-inspired, event-driven processing

An isolated asynchronous compliance and audit pipeline

Let's explore the architecture and the problems these patterns are designed to address.

1. Polyglot Persistence: The Right Database for the Right Job

Different types of application data have different requirements.…