Here’s what I learned building a subscription management system from scratch.

If you’ve ever built an app, you’ve probably started the same way I did a frontend, a backend, and a database.

It works. It feels clean. You ship features quickly.

But then the app grows.

You add things like subscription tracking, renewal reminders, analytics, maybe even notifications. Suddenly, what used to feel simple starts getting messy. Logic spreads across different parts of the codebase. Small changes start breaking unrelated features. Debugging takes longer than building.

This is exactly where most subscription management systems start to struggle.

The problem isn’t that the system is “wrong.” It’s that it was designed for a smaller version of reality.

In the beginning, a subscription system looks simple:

Store subscription details

Track billing cycles

Send reminders

But in a real-world scenario, things expand quickly:

Users can have multiple subscriptions

Each subscription has different billing…