One DB to rule them all? Hardly. Typical applications start their life with one DB, usually the one most fashionable, reliable, well-documented, referenced-on-google, or all of the above. Soon enough you find out not only that that DB you chose early on is actually wrong for you, but that it’s really hard to get rid of. In this talk you’ll see how in under two years, our application turned from single-DB, small & tidy, into a monster running four+ databases (on a good day), while testing and abandoning more than a few others on the way. I’ll discuss lessons learned the hard way on the process - about choosing a database, writing good code, making good products, and life in general.