Esper.io undertook a comprehensive redesign of its website to incorporate a dark mode, driven by the growing popularity and benefits of dark-mode interfaces, such as reduced eye strain and extended battery life. The redesign process emphasized accessibility, adhering to the Web Content Accessibility Guidelines to ensure proper contrast ratios for users with visual impairments. Esper employed a strategic approach using Webflow to establish a flexible design system, allowing for seamless theme switching and consistent styling across its site. The project involved updating typography, UI elements, and managing images to optimize the dark theme experience, while also leveraging modern image formats like AVIFF for better performance. The initiative resulted in positive user feedback, longer session durations, and lower bounce rates, demonstrating an enhanced user experience and reinforcing Esper's brand identity through a user-centric design and efficient engineering practices.