I sometimes hear people talking about the "infamous" Youtube algorithm that decides which videos to feature in trends or the local start page of Youtube.
Similarly, I've heard discussions about the ranking and matching algorithms of the dating app Tinder, which also seem to be shrouded in mystery, at least for people not directly involved in programming the app.
Those are just two examples, the principle is applicable to a wide range of similar apps/services.
There are obviously ways to influence an algorithm in one's favor, online marketing companies do this with rankings in Google searches, multi channel networks do this with Youtube channels, and Tinder allows users to buy subscriptions.
I, as a standard end user want to make sure I am using the the apps as efficiently as possible without using paid subscriptions, or monetary services in general, for that matter. In order to do this I feel like I need at least some understanding of the underlying algorithms of those apps.
What is good way to gather such information?