This chapter is all about confidence. Specifically, it is about how testing relates to our confidence in the cloud-native systems we build and particularly with regard to the pace at which we can build these systems. Our reactive cloud-native architecture gives us confidence that when an honest mistake is made, the blast radius will be controlled. Delivering features as a series of controlled experiments gives us confidence that we are not building too much functionality too fast before we have validated that we are building toward the correct value proposition. All our automated testing gives us confidence that we are building the system correctly and that there are no regressions, despite our rapid pace of innovation.
This last point is very important. Our automated testing does not give us confidence that we are building the correct system. It only...