At some point I would like to blog about it but right now I am under the gun to deliver a product so I'm writing a lot more code than english for the next few m

At some point I would like to blog about it but right now I am under the gun to deliver a product so I'm writing a lot more code than english for the next few months. In a nutshell I use Postgres for the relatively static data and Cassandra for the very high volume transactional data. I use Redis for ad-hoc data structures and some caching. The natural fit means I'm not jamming de-normalized data into a relational database for performance reasons. Hope this helps.