In this video, Sid explores building serverless asynchronous web applications using API Gateway and WebSockets on AWS. He explains the advantages of WebSockets over traditional polling methods for real-time communication between clients and servers. The architecture leverages API Gateway for WebSocket APIs, Lambda functions for processing messages, and DynamoDB for storing connection IDs and messages. This serverless approach enables true bi-directional communication, allowing both clients and servers to initiate messages independently. Sid walks through the implementation details, including configuring routes in API Gateway, using Lambda functions to handle connections and messages, and leveraging DynamoDB streams for asynchronous processing. This architecture pattern is particularly useful for applications requiring real-time updates like chat systems, multiplayer games, and financial trading platforms.