Undercover design happens when your job isn’t necessarily to provide design support, but you’re interested in achieving a quality user experience nonetheless. Developers, managers, and anyone else not filling the role of a designer can still affect the product being created, by offering input and advocating for users.
One of the most common ways to do undercover design is simply to speak up in meetings and informal discussions. Point out areas that you think might contribute to a negative user experience—things that might confuse or irritate users. But to qualify yourself to do this, you need to "eat your own dog food," as the saying goes, which means actually using the products you help create, and doing it as religiously as users will. This approach will help you become very familiar with the problems and annoyances of the application or site, and let you speak from a first-hand perspective. You can get an "up close and personal" look at the things people outside your office have to deal with to use your product or site successfully. You can find out for yourself how difficult it is to navigate the site or perform common tasks. As a result, you can speak from experience and point out specific issues that no one else may have noticed while developing the product, whether those encounters occur in official meetings, hallway chats, and even during happy hour. The more you know about the product and about how users work with your site, the more likely it is that the rest of the team will listen to you.
You don’t have to be a designer to be effective at improving the user experience!