File sync is one of those things that is easy to get 90% right and exponentially harder to get 99% right; there are a ton of edge cases especially when you intr

File sync is one of those things that is easy to get 90% right and exponentially harder to get 99% right; there are a ton of edge cases especially when you introduce cross-platform and mobile apps and all that fun stuff. It's actually a true bonafide distributed systems problem, where the implementation and service matter just as much as the specification.