[davidf18]

The failing here as in many cases such as a number of security breaches was a lack of investment. As someone with an engineering degree that worked as a VLSI design engineer, good engineering requires * backup systems *. This costs money that people don't want to spend. In some cases such as a startup they might be cash short, but many firms have the money but don't want to spend it ensuring that they have well engineered software that includes backups, up-to-date software and security upgrades, hiring (expensive) highly competent software engineers and consulting firms.

The mistake in this case was relying on one vendor for DNS. Amazon Route 53 would be a good alternate vendor for DNS, for example.