> Most companies will never have a million+ users. But what happens when yours does? What a time wasting question! It's exactly the sort of premature overdesig

> Most companies will never have a million+ users. But what happens when yours does? What a time wasting question! It's exactly the sort of premature overdesigning that you advocate against. The question is good for interviews to check for the scaling mindset but terrible in planning and design. The answer is: you use the same scaling techniques as published in numerous case studies/etc. and hire experienced engineers who've successfully scaled products before. The real answer is: you re-evaluate your systems to see how they should change to adjust to the need to scale; and you design systems that avoid assumptions that stop them from scaling.