In 1996, Yahoo! JAPAN was established by Yahoo (US: Altaba) and Softbank, and Altaba sold all the stock to Yahoo! JAPAN in 2018. Since the establishment, Yahoo! JAPAN has been the leading #1 portal site in Japan and unique users exceeded 48 million in 2018. We adopted Pivotal Application Service three years ago and current PAS capacity is 10 Foundations and 30K AIs, which supports 100K requests/second. In this session, Yusuke explains the challenges he faced and solutions he experienced to run and manage such a large-scale platform.