Our configuration service was tier three. No SLO, no pager, a single replica for a long time, and a line in the architecture document describing it as a soft dependency because clients cache their values and can carry on if it is unavailable. That sentence was true about the steady state and completely false about the one moment that mattered. It went down at 09:40 during a routine node pool rotation, which meant pods were also being rescheduled across the fleet. A pod that restarts has an em...