pm-practice strategy t’s important to think about platforms and ecosystems together as platforms by themselves aren’t useful unless someone is using them.
The term platform is thrown around in product marketing material to the point that its requires further definition. I like Bill Gates’s take: “A platform is when the economic value of everybody that uses it, exceeds the value of the company that creates it”. Ben Thompson offers a great post with more on this definition in The Bill Gates Line:

You can find more of his thinking here: https://stratechery.com/outline/platforms-and-ecosystems/
According to Ben Thompson, another dominant force in technology are aggregators which attract end users by virtue of their inherent usefulness:

I largely agree with Ben’s Aggregation Theory but I think aggregators often act like platforms as they extend out to adjacent markets.
Platform as a Garden
From Alex Komoroske’s Gardening Platforms (komoroske.com/gardening-platforms):

The role of a Platform PM
Making the Shift to Platform Product Management
Platform & ecosystem evolution
Making Sense of Technological Ecosystems
From Real-world platforms are messy

From A platform must be coevolved with its ecosystem

From The ideal goals of rational platforms

From Platforms don’t have killer use cases

Dealing with legacy platforms
Legacy platforms imply that there is a new platform on the table or at least on the horizon. It’s first worth the effort to diagnose the problems with the existing stack
https://jonnyleroy.com/2011/02/03/dealing-with-creaky-legacy-platforms/