In terms of the little guy having a saas, this is true for me...my saas basically is relying on s3 for both file storage and a json file per account to list out users allowed in the system. The only time it goes down is when s3 goes down or the occasional container restart.
Yes...think of it as layers... or manifests that point to another set of manifests global (list of users) -> accounts (have lists of users in them and role), content -> list of json files. I use a combination of json logic or simply listing out keys in a specific bucket...the speed of access doesn't seem to be something that bothers anyone, it started out as an experiment of less is more and because the app is not heavy on db searching etc rather only specific to account. I use oauth2 instead of relying on my own infrastructure and let people send out invites where they would use an email only but it must support the oauth 2 providers i already have in place. Basically, doesn't go down because it relies heavily on other things working that has teams of people working on them with gigantic resources. Don't get me wrong...I'm not saying it will scale to a million users, my clientele is mainly corporate that have a good amount per account sale but if it needs scaling, at least i didn't waste time and money on it during the interim and can always db-back it or dynamo it later.
