If you store data in something like AWS S3, "redundancy" and "backup" is handled by AWS. And scalability is a moot point if a single box can handle your load.

If you store data in something like AWS S3, "redundancy" and "backup" is handled by AWS. And scalability is a moot point if a single box can handle your load. When a single box cannot handle your load, you start one more, and then you start worrying about scalability. (Of course, YMMV, I guess there are cases where "one box" -> "two boxes" requires an enormous quantum jump, like transactional DB. For everything else, there's a box.)