I remember evaluating Riak back in 2011 or so for an analytics solution, but ended up going with a more traditional OLAP database that was a much better option.
It's hard for me to imagine where Riak would be a good option given how many choices we have today for various data stores.
Here are a few off the top of my head:
- the biggest online betting company in the world
- one of Japan's largest e-commerce sites
- a large Hungarian bank
- one of China's largest electronic manufacturers
- arguably Asia's largest or second largest messaging platform
- a significant Indian online-documentation provider
- one of the largest US insurance providers
- an Australian app analytics provider
- a European telephone services provider
- one of the world's largest travel sites
- an Asian-based credit-card fraud detection service
- a number of start ups in various industries
- me - I do my crypto taxes using a 5 node Riak cluster running on Raspberry Pi's
In the Basho era (up to early 2017), Riak may have only been targetted to larger players but now, when it comes to areas such as in-house data sovereignty, compliance (e.g. GDPR), the flexibility, speed and reliability Riak now provides plus being free to run, people from individuals to corporates are starting to wake up and see the advantages.
(edited in an attempt to improve list formatting)