There was a discussion of a self-built dropbox on the frontpage (https://news.ycombinator.com/item?id=47673394). This is just to show that dropbox is thoroughly tested for all kinds of wierd interactions and behaviours across OS using a very formal testing framework.
This is the kind of thing I think about when i see the mindset of “we’ll just replace all the SaaS with vibe code” pitches.
Not everything is a CRUD app website.
I was running my own hacky sync thing to the cloud a decade ago. I would never in my boldest dreams compared it to dropbox.
Even if you know the use cases, the edge cases could be 99% of the work. POCs are 100x easier than working production multi-user applications. Don’t confuse getting to a POC in 2 hours with getting a final product in 4 hours.