I hear this quite often but the case is that if you are looking for financing the main technical concern of the investors is how (and if) your application does scale - talking about SaaS. If a SaaS gets popular the new user load can be quite heavy and in the past there were a lot of story's about companies that needed to rebuild there system because of this (I think pipedrive was the last example I heard of).
Although it makes sense to ignore scaling at the beginning you need to design your application in a way that you can easily transition to something that can scale.
> the main technical concern of the investors is how (and if) your application does scale
How often is this borne of ignorance, though?
> in the past there were a lot of story's about companies that needed to rebuild there system
More specifically, are investors merely remembering the struggles of the dot-com boom, when transistor density was one thousandth that of today?
Internet usage (number of users and number of services each one uses) has grown, too, but I haven't seen statistics that suggest this would be more than 100x of 20 years ago.
> Although it makes sense to ignore scaling at the beginning you need to design your application in a way that you can easily transition to something that can scale.
This presents a false dichotomy. One doesn't have to ignore scaling at the beginning to make the decision to trade initial time-to-market for eventual "horizontal" scalability (usually what is meant by "can scale" [1]), but that may be what happens in practice.
[1] even though one can buy a remarkably large single server 3-6x price premiums over mid-range single servers, as well as use other, more traditional techniques, before "needing" to rebuild the entire system.
The investors I know and have to work with are mostly no technicians. They scan the news for investments and reported problems in growing business. If you can convince them that you thought about scaling issues and know how to solve them then they come up you should be fine :)
That belies the previous assertion that they're concerned with the "how" of scaling. What you're desribing is merely the investor (usually VC, which has been discussed here before) behavior of demanding that founders have a confident answer to potential challenges, even if it's bluster.
That's a situation fairly far removed from a VC refusing to invest because the company isn't imitating a FAANG's architecture.