Part of what you're saying is a good point, IMO. The people who transition the infrastructure from Level 0 to Level 1 won't be the same people in charge of infrastructure when it's time to transition from Level 17 to Level 18.
But however many levels there are from garage infrastructure to Big Tech infrastructure--even if there were only 2--someone will always have to decide that the time has come to transition from This Level to Next Level. Different expertise may be required to transition from L0 -> L1 vs L10->L11 vs L30->L31, but that expertise still matters.
And if I were the one who had to decide at any of those levels, I would want a well-designed plan for the next transition or two that was of the form: 'When [some measurement] reaches [some threshold] we will [change the infrastructure in the following ways...]'
> And if I were the one who had to decide at any of those levels, I would want a well-designed plan for the next transition or two
Right. This was really my (poorly-expressed) original point. Deciding how and when to scale is going to be a team and organization effort and decision. If it does come down to one guy deciding on something, then that's going to be the CTO. And if he/she is a good CTO, their decision is based on the feedback of a dozen people under them.
Scaling is a progression and no matter how fast your growth is, you do have time to come up with a solid plan and execute that plan. You don't need Facebook scale on day one even if you do become the next Facebook.
But however many levels there are from garage infrastructure to Big Tech infrastructure--even if there were only 2--someone will always have to decide that the time has come to transition from This Level to Next Level. Different expertise may be required to transition from L0 -> L1 vs L10->L11 vs L30->L31, but that expertise still matters.
And if I were the one who had to decide at any of those levels, I would want a well-designed plan for the next transition or two that was of the form: 'When [some measurement] reaches [some threshold] we will [change the infrastructure in the following ways...]'