Often that means spending 10x on building failure-tolerant architecture. For example, software may assume that files get corrupted sitting on a disk, and work

Often that means spending 10x on building failure-tolerant architecture. For example, software may assume that files get corrupted sitting on a disk, and work around that. But it turned out to be easier to build in the self-healing redundancy checks to the bottomest layer possible, to hard drives, and assume it's clean afterwards. Another thing I've heard of, is when they make space radiation-resistant CPUs, instead of making the CPU robust to miscalculations, it's easier to shield it as much as possible, use larger process nodes (like 110nm+). Of course, they also make all kinds of checks in the software as well, because they do real engineering.