In this episode we'll learn to write middleware, the foundational building block for Koajs and Expressjs.

Of course the best way to learn programming is to make stuff, so we'll build a "Session Management Middleware".

We'll start off writing a few tests using mocha and supertest , then we'll implement our Session Management Middleware first storing the session information in memory.

Next we'll take a quick look at RethinkDB , a cool new open source database, that we'll use to store our session information.

Lastly we'll refactor our middleware to save our session information using RethinkDB.

If you are unfamiliar with middleware or Koajs, please checkout my quick start screencast on those topics