The problem was that the engineers were building a scalable infrastructure rather than a scalable business.

from the article: "The average volume of Fast customers was low because most customers were from small businesses. And yet, every small business needed custom engineering work to be done, making integration slow. Several engineers mentioned how they did not understand how spending lots of engineering effort for each small client resulting in little revenue would result in building a company that could be worth $12B one day."

Sure, their primary problem was extravagant hiring, but I think this is still an important warning for developers working in fledgling companies that are appropriately cautious on the hiring side.

Heh maybe if they also didn't hire a bunch of engineers to scale out too, it would've helped..