It seems you paid yourself large salaries.
What was your burn rate?
I paying myself $1K salary and only because of the minimum wage law.
Even paying $3K to 4 people gives you ~ 21 months run
We had more people on our team than the four founders, and we had higher expenses being in separate apartments.
I like the way Stripe was built on a long vacation in Buenos Aires. If you're doing something that only requires internet to be built, your entire team could go on a several month vacation after demo day and it might result in a 50% lower burn rate depending on where you go, and probably 50% higher output.
