Re: It's not the sort of thing you'd want handling millions of rapid-fire financial transactions
I suppose you could take that question and ask folks that run things like redis, or memcache, or similar types of key value store systems.
The most popular use case that I see anyway is for caching and holding session data. Given the distributed nature of this feature it seems like it could do a lot for performance of caching more complex things closer to the client in a simpler fashion.
I'm not a developer and have no use for this myself, and am not, and never have been a cloudflare customer. I have worked with many apps that use memcache and redis over the years though (usually in addition to a database of some kind).
One developer I knew(but didn't like, and he didn't like me either) years ago thought he was smart and thought he needed just a couple of weeks to code a database caching layer in memcache to replace the mysql query cache. When I heard that I just laughed. He wasn't at the company much longer so never got to see what he might of come up with. (yes I know the mysql query cache is frowned upon, at the time it was required for our core application)
Heimdall is a MySQL database load balancer, analytics tool, and cache accelerator, something I have been using off and on for the past year or two. As an example they generally suggest using redis for (their) cache, though they can use Hazlecast and maybe one other tech too. Just mentioned them as an example of caching with MySQL anyway.
But it seems strange to me for someone to compare a key value store to a traditional database.