Data About People

The last board in the track ends on the question this lesson takes up: a log that remembers everything ends up remembering a great deal about real people. What should it keep, who agreed to it, and how does a system built never to forget forget one person?

Before you start. Stream Processing and Where Data Systems Are Heading built a design around one add-only list of everything that happened, the log, with every other store rebuilt from it by replaying it. That is all you need. This lesson asks what that design costs the people whose lives are in the list.