to be honest the testimonials are terrible.

> “Datomic added to DynamoDB was the only option that didn’t force us to sacrifice features or add the expense of developer time. Without it, we would have had to push back a lot more, as the features would have been too difficult.”

(https://www.datomic.com/the-brigades-story.html)

like, what? effectively useless information.

some of the other testimonials mention keeping revision history, which is neat, but why Datomic vs. others? it's pretty easy to keep revision history with other databases too.

It's not simply revision history, it's a complete record of everything with time, without re-architecting your data or app. IIRC datomic structures your data so that all transactions and state have a time dimension so you can go forward or back in time trivially (no special query, no temporal sql, etc.)

What happens when you have a legal obligation to delete or anonymise data for some reason?

There's https://docs.datomic.com/pro/reference/excision.html - but like in other data models you also might choose to not store sensitive infromation like PII in cleartext in the main DB at all. At least in earlier versions excision wasn't supported in the Datomic Cloud version.

Excision still isn't supported for cloud, it is / was on their plan but there was never any movement in that direction.

I wonder if this is related to lack of guarantees about actual data erasure on delete in the backing storage. A lot of users probably don't take this into account when building on top of cloud storage servies.

Not a good look when four out of the six companies behind the "customer stories" do not exist anymore (or at least their website is dead ...)