Here's a talk by Brandon Rhodes titled "Using Python to power Selenium at scale": https://www.youtube.com/watch?v=z1aUuqKg_gA
We'd have a deployment, and then launch a Selenium script to test the UI: login page load, registering a user, creating resources from the application, displaying elements, input text to validate, etc.
This is coupled with a lot of input validation, and a lot of actual unit tests for functions. We also decoupled functionality into pure functions.