[cldellow]

If you're doing a SPA, you can paper over the cold starts a bit, since the app itself will render, and it'll be background requests to load data that are impacted.

That still sucks, so then you can (hopefully) cache some things so that _some_ data begins to stream in. Or you can make it so your very high priority stuff has minimal dependencies - you can get a Lambda cold start in < 1s if your app only uses the standard library.

But still, in my experience, cold starts are a thing. If you have a high-traffic app or use Lambda warming, you decrease the # of people who experience a cold start, but at the end of the day, your p99 is going to be worse than a vanilla VM solution, because _some_ people will get cold starts. For some apps, that's OK - think line of business app where the first few pages can be served from static materials or cached materials, and you trigger the requests in the background.