Replay.io, a "time travel debugger" designed to record websites for bug fixing, has undergone significant design iterations to improve user experience and functionality. Initially, the product's interface combined a video player, timeline, and DevTools, creating a cluttered experience for non-technical users. User feedback revealed distinct needs for product managers and developers, prompting the development of a dual-interface toggle for QA and DevTools modes. This approach allowed for a more focused and effective user experience, with each mode catering specifically to its intended audience. The team's iterative design process emphasized simplicity without sacrificing professional-grade functionality, leading to a more intuitive and user-friendly interface. Despite launching with a refined design, the team continues to make improvements, focusing on creating a more airy and approachable interface while addressing user feedback and internal quality enhancements. This ongoing process reflects the dynamic nature of software design, aiming to deliver a product that feels great to use.