"Old" Yahoo! sounds so interesting, if you don't mind me asking, is there anything you would recommend to someone who wants to read more about it?

There was a book written a few years back that I haven't read but might answer some of these questions. "We Were Yahoo!: From Internet Pioneer to the Trillion Dollar Loss of Google and Facebook" https://a.co/d/9SuUXIn

I'll throw out Mr. Hedger Wang from Yahoo! as my nominee, he basically had the IE6 browser renderer in his head, and even though I never worked with him directly, just being able to ping on Y!M was an incredible help.

What made it special (2010-timeframe) was that we would do without thought what other companies struggled to do at that time (hot-hot failover, multi-region, "3 machine minimum" deployments), processing traffic for ~500M monthly users when spinning rust and 32gb of ram was considered "a lot".

My perspective on what happened is reeeally smart people solved really tough problems, then would either bail to Google (and later FB) to write the "v2.0" and solve those same problems but "better" or they'd go and start a full-blown company to sell that solution.

The tide rose around Yahoo! and both business-wise (and tech-wise), they didn't keep pace once their competitive advantage of "we can scale" dissipated.