Real-time Data Visualization Tech Stack

Here's our tech stack for the Chirpier service. One of the questions I've been asked is - how does Chirpier (www.chirpier.co) support real-time data visualization and monitoring alerts at scale, with the ability to support millions of messages a second?

I thought I'd share our stack here on Share Stack:
https://stackshare.io/chirpier/chirpier