Introduction
Building a scalable e-commerce platform is no small task. It requires careful planning around your data model, your caching strategy, and the way your services communicate with each other. In this post I'll walk through the architecture choices that worked well for me.
Choosing the right architecture
A monolith is fine when you're just starting out. But once you cross a certain traffic threshold, splitting your application into smaller, focused services pays off.
- Cart service handles the shopping session and pricing.
- Catalog service owns products, categories, and inventory.
- Order service manages checkout and fulfillment.
Data modeling
Relational databases like PostgreSQL give you strong consistency guarantees, which you want for orders. Use indexes on the columns you query most, and keep frequently accessed data in a cache like Redis.
Caching
"There are only two hard things in computer science: cache invalidation and naming things."
Cache product listings aggressively, but invalidate carefully. A simple rule: cache at the API boundary, not inside business logic.
Final thoughts
Start simple, measure, and split services only when the pain justifies the complexity. A well-tuned single database often beats a badly orchestrated microservice mesh.