Last I heard, Amazon does a 25-way join on their customer tables to print a shipping label. Now that's quite an albatross for developers and DBAs to carry around!

Mark was a perfectionship in releasing a working product. That doesn't mean it was good from a programming standpoint, but it was tested and always worked well.

eBay is the poster child for shitty software. At one point their CTO was requesting one Sun E10k per month ($2 million each fully populated) because of how slow and leaky their Windows code was. The board said no and they had to fix it.

Wouldn't this just be a classic case of survivorship bias? For every Amazon and Facebook there could be a number of companies that did similar things and fell apart.

Good code quality doesn’t guarantee success. However, those two data points indicate it may be necessary if not sufficient. There are only 4-5 tech companies operating at that scale with proven business models. Google and Microsoft being the primary others.