(Presented by Anthony Eden) 3 years, thousands of hours of work, new clients, new documentation, a series of releases… redesigning a public web service API is a major undertaking. This is the story of the DNSimple API v2, a project the started with a single, innocuous GitHub pull request with the title “Proposal for versioned API” in December 2013, and which came to its conclusion, a successful general availability launch, at the end of 2016. I will explain some of the decisions we took over the last 3 years that shaped the development of the API as well as challenges we faced, and provide you with tips and techniques that may help you in your next major API project. The chief architect of the API, Simone Carletti, will be on hand as well to answer questions. Finally I’ll answer the question: what’s next?