Let me paint you a picture of something that has undoubtedly happened to all of us at one point.

Upon making a purchase from an online retailer, you notice a mistake with your order; you ordered the incorrect size of shirt…. for example.
In an attempt to rectify this blunder you begin to search the website for a customer service section only to spend the next ten minutes of your life diving deeper and deeper into the many hyperlinked pages until finally giving it all up as a bad job; resigning yourself to live with whatever mistake you’ve unintentionally made.

Now, putting this obviously-hypothetically-I-am-totally-not-speaking-from-experience example to the side this is a textbook case of a website having an intentionally bad user interface. One that essentially frustrates the customer into a state of fuming passivity.
From the companies perspective on the one hand by not giving the customer the ability to modify (or possibly refund) that sale you, as a business, maintain a debatably stable stream of sales and income.
However, on the other you are also leaving the customer with a very negative experience which they are sure to then go off and rant about in a thought piece on their personal blog.
Due to the fact that digital marketing does rely on a decent amount of word-of-mouth, this is far from the best situation to leave the consumer in.

So,
How, as budding UX designers, can we rectify this problem?
Well there are many different strategies that developers implement to better enhance their website design but the specific one I will touch on today is ‘usability testing’.
This, as with mostly everything can be broken down into different pieces however as a whole it is concerned with having user generated feedback dictate design decisions. Basically, it’s having someone sit down and attempt to use your website while you ask them questions. The exercise we conducted in class reflects a moderated testing environment; having the tester present while the subject navigates the website in order to complete a task.

This moderated testing style allows the UX designer to gather a lot of really valuable descriptive and qualitative information about the functionality of their website.
“What aspects really worked well?”
“What functions could be improved?”
”Where any elements on the site confusing or difficult to navigate?”
By conducting this study over a range of testers a designer will be able to understand if there are any aspects of the site which need to be reorganized, altered or removed.

Although this type of testing can sometimes be rather costly and time consuming I feel it’s the most efficient way of ensuring a website is easy for consumers to navigate through. Especially within an Ecommerce context, you want to make sure that a customer is digitally supported throughout each step of their online shopping experience. Good design will almost guarantee a good conversion rate and, if not, it definitely won’t hurt your chances for retaining customers. As humans we want the things we interact with to make a logical sense and that, in effect, is the purpose of UX design and usability testing; to make sure things work in a understandable, predictable way.
”To put it simply, UX is important because it tries to fulfill the user’s needs. It aims to provide positive experiences that keep users loyal to the product or brand. Additionally, a meaningful user experience allows you to define customer journeys on your website that are most conducive to business success.”
Source : https://www.rocket55.com/ux-design-the-importance-of-user-experience/