I'm pretty averse to no-code, etc. Is there some event-based set of libraries that have a common protocol which have all the boilerplate code in place to connect to popular APIs and receive webhooks from the likes of Dropbox, Google Drive etc.

In other words a programmable ecosystem like IFTT?

Huginn has existed for years: https://github.com/huginn/huginn

It also runs on a free-tier Heroku Dyno.