TL;DR: TokuMX (MongoDB upgrade) through Redis with Go on the back end and Node.js for the API. The biggest take-away for me was that someone is selling ($2500/

TL;DR: TokuMX (MongoDB upgrade) through Redis with Go on the back end and Node.js for the API. The biggest take-away for me was that someone is selling ($2500/server/year for hot backup + support) an improved ('accelerated speed for inserting data as well as compression') GPL2 MongoDB.