Event uploads fail differently from normal office uploads. A wedding guest may move between venue Wi-Fi and mobile data, lock the phone while a video is transferring, or close the browser as soon as the progress bar reaches 100%. Hundreds of devices can share one access point, and users rarely wait around to diagnose an error.
The usual POST request plus optimistic success toast is not enough. A reliable browser flow needs a small protocol that distinguishes local preparation, network transfer, server acceptance, media processing, and final availability.
This article describes a platform-neutral design for that protocol.
The five states users actually experience
Model each file as a durable state machine:
