Xiaomi is steadily eliminating outdated legacy code. In HyperOS 3.1, certain system modules have already commenced the process of removing SDKs that hark back to the MIUI era. HyperOS 4, slated for release in August this year, is projected to emerge as Xiaomi's inaugural "zero legacy" system version. HyperOS 3.1 has embraced Google's Flutter toolchain and the Rust programming language to overhaul core system applications, championing a modular design approach. Serving as a transitional iteration, it has introduced the native HyperOS SDK while still retaining the MIUI SDK. The latest weather application within HyperOS has adopted Flutter code, with its fundamental logic rewritten using Rust. HyperOS 4 is set to deliver a unified UI rendering experience and ensure logical stability. Once the code migration is finalized, it will evolve into a genuinely independent operating system. Nevertheless, this shift may not be user-friendly for owners of older phone models, as outdated devices are unable to install new applications independently to access new features. The removal of legacy code, however, can help alleviate performance bottlenecks in mid-range and low-end devices. Based on these developments, the media speculates that HyperOS 4 will undergo a "rebirth," emerging as the most stable and streamlined system update in Xiaomi's history.