Adding an in-app notification feed to a Next.js application can be simplified using Knock's drop-in components, which manage complex tasks such as real-time updates, read/unread states, and pagination, while allowing for user experience customization. This guide walks through setting up a notification system by first installing necessary dependencies and configuring environment variables, followed by wrapping the application with Knock providers to ensure access to Knock's context. It details the implementation of Knock's NotificationIconButton and NotificationFeedPopover components for displaying notifications and managing message states, while emphasizing the use of Knock's Node.js SDK for triggering notification workflows. The final step involves configuring workflows in the Knock dashboard to define notification templates and conditions, resulting in a functional system that offers real-time updates, unread counts, and a clean interface, all with minimal complexity.