Comment by ochiba

> And 'synchronisation' as a practice gets very little attention or discussion. People just start with naive approaches like 'download whats marked as changed' and then get stuck in the quagmire of known problems and known edge cases (handling deletions, handling transport errors, handling changes that didn't get marked with a timestamp, how to repair after a bad sync, dealing with conflicting updates etc).

I've spent 16 years working on a sync engine and have worked with hundreds of enterprises on sync use cases during this time. I've seen countless cases of developers underestimating the complexity of sync. In most cases it happens exactly as you said: start with a naive approach and then the fractal complexity spiral starts. Even if the team is able to do the initial implementation, maintaining it usually turns into a burden that they eventually find too big to bear.