E-commerce websites have evolved significantly due to advancements in front-end and back-end technologies, driven by the need for efficiency amid growing traffic and competition. Speed is critical, as sites must load quickly to meet user expectations, utilizing techniques such as caching and Webpack to optimize performance. Caching, especially with Service Workers, accelerates site loading, although challenges with browser support necessitate alternatives like local storage. Webpack enhances compression and pruning of unused code, improving load times. UI and UX design are crucial, with custom web fonts and image parsing strategies like SVGs and lazy loading being employed to enhance user experience while maintaining performance. Customer satisfaction hinges on interactive interfaces and efficient search functionalities, with progressive web apps (PWAs) becoming increasingly vital for leveraging web technologies. Testing across devices and browsers is essential to ensure consistent performance, with tools like LambdaTest offering robust solutions for detecting and resolving issues, making it easier for developers to maintain and enhance e-commerce platforms.