Have you ever feel that an API doesn't make sense at all? What about simple changes that break the clients? Or missing/wrong documentation? Does this sound familiar? This even gets more interesting when that horrible API, well... is yours. We all have been in the situation where the API codebase is awful but we keep adding functionality and increasing the technical debt. Can we change this? How can we do it? And what is the cost of having a great API that allows your product, and engineering teams to move fast and keep the peace of the market?