In September 2015 I had to (re)write some applications in NoedJs. Those applications were written in Express, but I was all into ES6 at that time and wanted something new. Some googling and I ended up spotting KoaJs.
After watching this wonderful videos by James Moore and reading the Koa Wiki I eventually fell in love with this new framework created by the same team that's behind Express.
To give it a try and learn I decided to convert this excellent Express tutorial written by Scott Smith, to KoaJs.
I won't rewrite the whole article, but I'll just share my code, which you can find here on GitHub, so you can follow Scott Smith's post, but write KoaJs code instead.
Please note that I decided to drop mongoose in favour of Monk, just because I knew mongoose very well already and wanted something more lightweight and fast to concentrate on KoaJs and generator functions.
Note that, in a real world application, there's no doubt, I'd stick with mongoose.