After 15 years of running the Yahoo! JAPAN Auction app, it had many technical problems. We decided to fix these problems by rebuilding the app completely from scratch.

The renewal was very difficult, but we often felt that it was worth all the hard work.

For people who have problems with quality or technical debt in long-running services, we want to share our real examples. This will give you a chance to think about updating your own services and planning for long-term development.