Tap Send on WhatsApp: The 5 Stops Your Message Makes

What actually happens in the second after you tap Send on WhatsApp? We follow one message, "Running late, sorry.", from Lahore to Toronto through five stops, and find out why WhatsApp's servers can't read a word of it. ⏱️ Chapters 00:00 One message, five stops 00:25 Stop 1: The connection that's always open 01:26 Stop 2: Locking the message (Signal Protocol) 02:44 Stop 3: The server and the first tick 03:06 Stop 4: Online vs offline (the 30-day wait) 04:13 Stop 5: How blue ticks work 04:36 Linked devices and group chats 05:13 The whole trip 📚 Sources WhatsApp Security Whitepaper: Signal Protocol, key registration, Noise transport encryption, Sender Keys for groups WhatsApp Privacy Policy: delivered messages are deleted from servers; undelivered messages are kept encrypted for up to 30 days Meta Engineering (2021): "How WhatsApp enables multi-device capability without compromising end-to-end encryption" WhatsApp Blog (Jan 2012): "1 million is so 2011" TechCrunch (Oct 2020): WhatsApp is delivering roughly 100 billion messages a day Some details of WhatsApp's internal systems aren't public. Where the video says "apps like this typically…", that's how this kind of system is usually built, not a confirmed WhatsApp detail. 🔔 Next: what happens when you tap PAY. Subscribe so you don't miss it:    / @underthetap   🐦 X: https://x.com/UnderTheTapTech 📩 Business: underthetap.channel@gmail.com Narration voice generated with Kokoro (open-source text-to-speech). Script, research, and animation by Under the Tap. #WhatsApp #SystemDesign #HowItWorks