Our internal QA (quality assurance) process always comes before UAT (user acceptance testing) and is conducted by writers, designers, and developers to ensure that all aspects of a site are polished before we call it "finished."
Then, our client takes a look, browsing their new site as a user would and going over every page to make sure that it functions and feels how they’d imagine.
At EA, UAT usually takes place over the course of a week, giving our client’s organization time to pore over the new site and ensure everything is working properly. If there are any bugs, the client submits a ticket using a simple interface that’s right on the page, and our devs get to work fixing it before handoff.