NTT has been using OpenStack in production since 2013 and has contributed significantly to the OpenStack community. Initially, NTT built a proprietary system on top of OpenStack to address issues around stability and operability. Over time, NTT shifted to an "upstream first" approach, contributing fixes and features to the community. Currently, NTT runs a highly available OpenStack deployment with features like VM high availability contributed back to the community. NTT continues working to integrate OpenStack further into its business and explore new use cases like NFV.