When you have a billion users, people notice. That’s where our story about DevOps and Yahoo! starts. For Kishore Jalleda and Gopal Mor, both engineers at Yahoo!, when something goes wrong on a Yahoo! page, people will notice. Correction: a lot of people will notice.
Of course, Yahoo!, like all services on the Internet, constantly improves its products. In fact, they have 100+ iterations and experiments happening at any given time. Some changes bring new innovation to the forefront and others alter the user experience.