That’s totally a fair point. I could have given a more concrete talk about how I’ve done these things in real systems (and the original version of this talk, presented internally to my company, had more real details and spoke very candidly about mistakes that I’d made along the way). Here I wanted to give more of a “here’s how you might want to structure your thinking, along with some basic design principles” kind of talk - I wish I’d had time to give more detail!