An instant page is one where a typical user click has the result fully rendered inside 100 milliseconds (almost imperceptible latency). That's an incredibly ha

An instant page is one where a typical user click has the result fully rendered inside 100 milliseconds (almost imperceptible latency). That's an incredibly hard to reach target. Establishing a secure connection from the browser to a server requires several round trips - 1 for DNS lookup, 1 for TCP handshake, 2 to establish the TLS connection, and 1 for the HTTP request. If you divide your 100ms perf budget equally between them that means your servers can be no more than 1800 miles away from the user using (100ms c) / 2 (for the round trip) / 5 requests*. Using TLS 1.3 removes one round trip which is definitely a good optimization. That's before you've even started any serverside rendering, session handling, db connections, etc. Even with a really good edge network that's going to be incredibly hard to achieve. I'd love it if every website served a page in 100ms, but it's never going to happen. I got https://ooer.com https://ooer.com down to below 500ms for myself (495ms last time I checked) after a fair bit of effect. Getting any lower would be a waste of time. Users can wait an extra 400ms.