During December 2025, DTM9025 focused on backend reliability for the keiyoushi/extensions-source repository, addressing a critical issue affecting image URL retrieval. By leveraging Kotlin and backend development expertise, DTM9025 implemented a hotfix that reordered server fallback logic to prioritize operational subdomains, which reduced image load times and improved overall page performance. This solution enhanced reliability during subdomain outages, ensuring a more consistent user experience. The fix was designed for rapid deployment with minimal production risk and included thorough documentation and communication with relevant teams. DTM9025’s work demonstrated depth in diagnosing and resolving infrastructure bottlenecks using targeted, maintainable code changes.