Railway does not modify the source code. It only reads the source code.

Rolling back a service only routes all traffic to a previous deployment.

yes, but this is for a railway function, not an actual image

rollback on a railway function does not affect source code

According to Railway docs:

A deployment rollback will revert to the previously successful deployment. Both the Docker image and custom variables are restored during the rollback process.

According to Sam's DMs more like

would it be more intuitive for the code of the railway function to also change when rolling back a function?

because, when i look at the UI i see code differing from the function that is actively running. this is quite confusing as a user

ive edited the code of a rolled-back function and caused it to brick some stuff twice at this point

it doesnt make much sense if the intended behavior is to "rollback"

So as it is, "source code" is basically just a "setting" from the standpoint of the platform. And what you see everywhere in the UI, regardless of which deployment you rollback to, is the latest values you've configured as we consider this a "desired state".

We've talked internally before about whether this is desirable. I understand the confusion for sure.

For now at least you can copy/paste the source code from the deployment you rolled back to