[Michielvv]

In the projects that I was involved in in the past years, the ones that decided to build a scalable infrastructure before gaining traction were exactly those that were burning cash on infrastructure. There is just a reasonable minimum of servers you need to run such an infrastructure and then you need something similar as a staging environment to make sure it all works together correctly.

That being said, there are of course choices that can be made early on that will help you in case you need to scale at some time. Spending a bit of time thinking through what would happen if you do need to split up and scale out your system will help you avoid pitfalls such as relying too much on the local filesystem being shared across pageviews.

In general I believe there is more benefit on spending time on performance early on. (not caching, that is just postponing the problem) as it benefits not just your ability to run on a single system for much longer, it will also make life better for your users.

[salman89]

Scalable system does not imply needing many machines. There is no reason you can't just deploy your entire system on a single host, but maintain the ability to reconfigure exactly when needed.

But yes - its about finding the right balance.