For as long as we’ve been talking about services, we’ve been talking about data. In fact, before we even had the word microservices in our lexicon, back when it was just good old-fashioned service-oriented architecture, we were talking about data: how to access it, where it lives, who “owns” it. Data is all-important—vital for the continued success of our business—but has also been seen as a massive constraint in how we design and evolve our systems.