[snowwolf]

There is an argument that you should absolutely be optimising for day 1. One of your biggest advantages as a startup is agility. Until you've hit upon product/market fit, you want to choose tools that enable you to iterate fast.

[dcosson]

I'm talking about literally day 1, not just like the first phase of the company. If a startup is exactly a single day (or single week) ahead of the competition such that the productivity on that day is make or break, that goes way beyond agility and is probably just not a very good opportunity.