Someone told me once it's more important to design things to scale 1 or 2 orders of magnitude and be easily replaced. What you think you'll need 2 or 3 orders of magnitude from now is rarely what you need when you get there.
Yes, but it's also easy to get bogged down reimplementing, right when you have more important things to focus on to keep up with growth. Designing things to be easily replaced is easier said than done.
