High-level Design of WhatsApp

High-level design

At an abstract level, the high-level design consists of a chat server responsible for communication between the sender and the receiver. When a user wants to send a message to another user, both connect to the chat server. Both users send their messages to the chat server. The chat server then sends the message to the other intended user and also stores the message in the database.

The following steps describe the communication between both clients:

1. User A and user B create a communication channel with the chat server.
2. User A sends a message to the chat server.
3. Upon receiving the message, the chat server