Trunk-based development with feature flags enhances software delivery by enabling developers to merge small, frequent updates into the main branch while keeping features hidden until ready, minimizing merge conflicts, accelerating integration, and ensuring controlled feature rollouts. The article guides developers through creating a feature branch and using the Harness React SDK to implement a flag in a project, using Vite, React, and Sass to change the look of a logo in a navbar. It explains the steps to set up a project with Vite, create a feature branch, and add CSS for the component, emphasizing the importance of keeping features disabled until ready for release. The use of feature flags allows for targeted testing and separates deployment from release, enabling the code to be deployed to production while remaining hidden until the flag is toggled, ensuring a smooth and controlled release process.