WhatsApp having less complexity? Care to elaborate on that?
I'm aware they scaled to 1B+ users with ~100 engineers but I'm failing to see why they'd be working on less complex problems.
I'm aware they scaled to 1B+ users with ~100 engineers but I'm failing to see why they'd be working on less complex problems.
Operating on almost all native platforms, at this scale, with those constraints, isn't something i find much easier than building a feed.
On Whatsapp the ordering guarantees are limited to within the thread and server side timestamps are good enough for the most part to enforce it. Whatsapp/messaging is a very horizontally scalable problem. With feed (assuming) you have a fully personal feed the storage alone is a pain to manage and optimize.
Now of course you can reimplement an ordering mechanism on top of an unordered one, with lost messages detection etc on the client side, and let the server be loose.
but that means reimplementing that logic on every client codebase.