[sodapopcan]

Lots of answers here including one from Chris McCord himself, but I'll offer my take based on my professional experience developing web apps (though I've never used Phoenix professionally):

A large majority of businesses out there start off targeting one region/area/country. The latency from LiveView in this scenario is imperceptible (it's microseconds). If these businesses are so lucky as to expand internationally, they are going to want to deploy instances of their apps closer to their users regardless of wether or not they are using LiveView.

LiveView could be a huge help to these startups. The development speed to get a concurrent, SPA-style app up and running is unparalleled, and it scales really well. My guess would that be that people who are worried about the latency here (which is going to exist from any SPA anyway) are the ones who are developing personal pages, blogs, educational material, etc. that they are hoping the world is going to see out of the gates. In this case, LiveView is not the answer!!! And as I've stated elsewhere 'round here, LiveView does not claim to be "one-size-fits-all". If latency really IS that big of a concern, LiveView is not the right choice for your app. But there really is a huge set of businesses that could really benefit from using it, either because they are a start-up focused on a single area/region/country, or they are already making tons of money can easily afford to "just deploy closer to their users" and could benefit from LiveView's (and Phoenix's) extreme simplicity.

[louissm_it]

Pretty much this. Also, I’m not sure most people realise how incremental LiveView can be. You can use it for a little widget on any page and later swap in a react component if you truly need one (which most apps probably don’t).

It’s not designed to run the NY Times. But it is a super useful tool that will benefit a ton of apps out there.

[joppy]

Is microseconds correct? Even with a good connection in online games I’ve only seen ping latencies of 3ms or so, and a more common range on an average connection is 20ms-50ms.

[sodapopcan]

Should be, though milage may vary, of course. I'm having trouble finding a better example but https://elixir-console-wye.herokuapp.com/ is made in LiveView. You can try it out and see what you get (I have no idea where it's deployed, it's a phoenixphrenzy.com winner and plenty more there to browse through). Its payloads are a bit larger than some typical responses I have in my personal apps and I'm seeing 1-2ms responses in Toronto, Canada (chrome devtools doesn't show greater precision than 0.001 for websocket requests).

[coryrc]

ms is milliseconds

[sodapopcan]

Yep, which is what I meant in my comment you're replying to (as per my statement that devtools only report to the 0.001). But as pointed out by jclem, I'm probably wrong about microsecond response times anyway. I'm very likely thinking about the MICROseconds I see in dev, which of course doesn't count :) But with the heroku link above, I am seeing as low as 1-3 MILLIseconds in Toronto, Canada.

[jclem]

One light-microsecond is about 300 meters, this must be milliseconds.

Edit: Just saw that this was already pointed out. Apologies, didn’t mean to pile on.

[sodapopcan]

I pointed out below that I actually DID mean microseconds but likely skewed by times I was seeing in dev. Hopefully it does not take away from my point that response times are still imperceptible when in roughly the same region (I'm seeing 1-3 milliseconds in the heroku-hosted LiveView app I linked below).