POC whipped together without good architecture. Having proven itself, usage increases until the application starts to burst at the seams. Program must be redesigned, avoiding performance gotchas.
I still think Django + the ORM give you a lot of runway before performance should be a concern.
I also realized mid project that the default rest framework doesn’t support good api model generation from OpenApi or vice versa. And most devs didn’t understand why using untyped dicts everywhere was bad.
In all transparency, I am openly biased for static typing and have a background in java, c# and Swift.
So what we ended up with looked similar to a statically typed language but without the tooling or performance.