>> While RDS limits connections to 16,000 PlanetScale has been designed to scale upwards of 250,000 connections to a single database.
Curious to know what kind of applications would need more than 16,000 connections to a single database? In a typical application, that I know, a single database is connected by few replicated application servers. The count could vary from one to a few hundreds. I am not sure scaling the number of connections can solve the real scaling problem. Let’s say you support 250,000 connections and every connection is sending some queries at the same time. Is the database capable of handling that many queries, if not then what is the point of supporting so many connections.
The e-ink displays are a bit costly. Otherwise I would get a few of them and would replace all the paper calendars at home. Simply a calendar, no internet, low power. Not raspberry PI based, some low powered microcontroller simply displaying a paper like calendar and nothing fancy.