Moving from "Feature" to "Platform": Why I’m building a plugin system for my SaaS.

I’ve been building Crate.cc as a resilience-first gateway (handling stuff like Waterfall Routing to save on cloud costs). But after talking to more devs, I realized the real "hair on fire" problem is Legacy Migrations.

I’m currently architecting an extensible plugin system to solve this. The first pass uses JSONata for inbound/outbound body mapping, so you can map modern frontends to legacy backends without a 3-month rewrite.

The Business Logic:
I’m using this to differentiate my tiers in a way that protects the infrastructure.

1. Performance Gating: I'm gating the execution time of plugins. Light transforms stay on the Hobby plan; compute-heavy transformations move to the Business tier.
2. Hardware Isolation: For Business customers, I’m deploying dedicated bare-metal hardware. Their plugins run in total isolation—no "noisy neighbors."

I’m curious if other founders here have seen success gating "compute time" or "hardware isolation" as a tiering strategy?

Also, if you're currently stuck in a migration nightmare where you're trying to reshape data in-flight, I'd love to hear what transformations are giving you the most trouble. I'm building out the first set of pre-built mappings now.

#SaaS #BuildInPublic #Infrastructure #Golang