I led a migration from Mongo to Riak at Shareaholic about 12 years ago: <a href="https://www.slideshare.net/slideshow/migrating-to-riak-at-shareaholic/14130612" rel="nofollow">https://www.slideshare.net/slideshow/migrating-to-riak-at-sh...</a><p>It was successful at first, but ultimately we traded one set of problems for another (how novel, I know).<p>In particular, I underestimated the pain of troubleshooting the database itself. Riak was a new product, we were a small team that had never run anything on BEAM, and ultimately we lost too many days debugging and trying to make sense of Erlang stacktraces.<p>The Basho folks were great, and to this day I appreciate how quickly they fixed a number of bugs for us. But ultimately it wasn't enough -- we found problems faster than they could be patched.