Five Unbelievable Secrets of Reactive Programming the Experts Don't Want You to Know!, Greg Heo
Don't be fooled by the cheesy title. This article, recommended by Max, explains the ways of thinking with reactive programming - and how it's really not that different than "traditional" programming. A quick read.
Principles of Microservices by Sam Newman
A video! Because let's be honest, even though we love recommending articles, we watch a ton of videos. This one was recommended by Jacob - it is great as an introduction to microservices for beginners and it holds guidance on implementation for more experienced folks.