The Japan Gov has adopted Drupal 8 as its official statistics system.

Session Slide is here.

https://www.slideshare.net/ki3104/the-japan-government-has-adopted-drupal8-for-its-official-statistics-system-drupalcon-nashvill...

The Japanese government has adopted Drupal8 as a portal site for huge numbers of statistical information. The site was renewed on January 4, 2018

Portal Site of Official Statistics of Japan 
https://www.e-stat.go.jp/en
https://www.e-stat.go.jp/

e-Stat is a resource with huge amounts of data.
 It is one of the world's leading statistical portals boasting terabytes of data. 

There was challenge as to how to make the huge preexisting back-end system built with Java＋Oracle compatible with the front end system which can be updated by the administrator. Drupal was used to solve this issue. 
Drupal uses the new Decoupled as a front end controller. We used its architecture, developing a user friendly interface and augmentability, effectively applying Drupal's merits to the fullest to create a seamless integration. 

These case studies demonstrate that Drupal will have huge impacts with its role in integrating large systems and web systems. We hope to convey this to the Drupal Community around the world.