alt Hacker NewsTwitter wasn't built by 1000 engineers at 350k/yr.
It had to hire them later on. Because when there are users - you need support, take out fires etc.
And this exact thing will happen with any homebrewed SaaS.
You either run a business or play tech company making your own saas instead of focusing on your business.
Sure you can do both in very rare cases - if you are SpaceX or similar, otherwise you are shooting yourself in the foot.
No. They hired 1000 people to help them justify funding rounds.
Even then, startups prioritize growth over efficiency. So maybe 100 people would have been fine but 1000 gets them a 5% growth improvement in growth.