So you created a great new Web application! That’s great, and because it’s new, it’ll be easy to maintain… until it accumulates more and more features, and data, and bloat. Someone might then suggest that you refactor your system into one using “microservices,” breaking your large, uniform system into a number of smaller ones. Microservices can indeed be helpful, but it’s important to understand what they are, and what they do. In this talk, Martin Fowler describes what a microservice is (and what it isn’t), and what we’re likely to find as we migrate toward them in our Web applications.