Everything is stored in the cloud. On-premise or hybrid solutions are available with special enterprise pricing. Tracts uses several secure cloud services. All of the major code base is stored and accessed on Digital Ocean. All of the “objects”, such as the PDFs are stored on the Google Cloud.
DigitalOcean security and compliance information can be found here: https://www.digitalocean.com/security/
Google Cloud Services security and compliance information can be found here: https://cloud.google.com/security/