Your demo works. Your user journey might not.
A polished screen can hide a journey that stops halfway. Readiness lives in the connections between features.
What you might notice
An owner sees registration, a checkout screen, and a dashboard, and reasonably assumes a customer can move between them. Those screens may have been built in separate sessions with different assumptions.
An example
A fictional booking app creates an account and accepts a booking, but the confirmation job never runs. The dashboard displays a success state even though no confirmation has reached the customer.
Why it matters
Customers cannot tell whether a booking exists. Support has to reconcile records manually, and the owner may mistake a UI success message for a completed service.
How we check
We trace one agreed journey using representative accounts, check persisted state and integration responses, and repeat the journey with missing data and failures. We distinguish code review from behavior we actually exercised.
What a fix should achieve
A journey is complete when the intended user outcome is reached, failure states are clear, and the result can be verified. The acceptance check should cover the whole path, including external effects.