#17: Read Now - Architecture Overview Chat Application (4 minutes)
Thank you for the article.
I would like to clarify information here
> When a message gets sent, the WeChat server stores it because the receiver might be offline. And a notification gets delivered to the receiver when it's back online again.
From WeChat document, it seems like they will only store your message in case the receiver is offline. They store messages in a short amount of time
> We do not permanently retain the content of any messages on our servers whether they are text, audio or rich media files such as photos, videos, or documents, unless you or your recipient saves them as a Favorite. Once 72 hours has lapsed since you sent your chat message, or 120 hours for images, audio, videos, and files, WeChat permanently deletes the content of the message on our servers. Upon deletion, neither WeChat nor any and third party will be able to view the content of your message.