S3 has touted 11 9's for many years, so before shardstore definitely.
The 11 9's is for durability, which is really more about the redundancy setup, erasure coding, etc. (https://cloud.google.com/blog/products/storage-data-transfer...)
fwiw availability is 4 9's (https://aws.amazon.com/s3/storage-classes/)
That’s a good point!
I think I overstated the case a little, I definitely don’t think automated reasoning is some “secret reliability sauce” that nobody else can replicate; it does give me more confidence that Amazon takes reliability very seriously, and is less likely to ship a terrible bug that messes up my data.