Discussion on: How do you wrap your head around observability?

Two dimensional arrays.

But not 'spatial x spatial',
Rather 'spatial x temporal'

You end up with essentially a timeline:

An 'observer' creates a timeline (usually by calling next(), complete(), or error() as events are observed) - and the timeline is then an 'observable.'

In JS, RxJS provides an excellent library for this, as well as a swath of 'operators' (creating a new 'timeline' from a given 'timeline') that makes for really great dev exp - both in terms of writing declarative code, and in terms of dealing with a frontend environment that's driven by observed user and/or server events!