In this chapter, we talked about what postmortems are, when we should write them, and how to write, discuss and analyze them. We also talked about keeping blame out of postmortems and helping your team to prevent future issues by prioritizing what comes out of the postmortem process.

As an SRE, or as part of an organization that wants reliability, postmortems are the transition from dealing with the present to dealing with the future. Everything above postmortems in the hierarchy is about the future—planning and improving processes. Everything below (monitoring and incident response) is about dealing with the present. Postmortems allow us to look at the past, before we start thinking about the future.

In the next chapter, we will talk about testing and releasing, where we think about code we have written and how we introduce it into the world. We have finished looking at incidents and now will move on to the constant evolution of our products and services.