Data stays in Russia
Below is what can be checked: where the server stands, how contacts are stored and what happens when you ask for erasure.
A server in Russia, dedicated environment
The application, the database and the queue run on one machine in a Russian data centre, apart from other customers. Only the web and the API are exposed, over HTTPS.
Contacts are stored as a stable key
An address or a phone is reduced to an irreversible key used for deduplication. The key lives outside the database, so an export of the database does not restore the contacts. A decryptable copy of a phone or a name appears only with your explicit permission and is encrypted separately.
Tenant isolation enforced by the database
Every row belongs to its workspace, and the database refuses reads and writes when the context is not set. That is a database rule, not an application check somebody can forget.
A journal of operations
Actions on the data are written to a separate journal with a linked chain of signatures: an entry cannot be altered or removed unnoticed. The journal is available to you in the app.
Erasure on request
An erasure request is executed per subject: the data and the events are wiped and a record of the erasure itself remains. The suppression list is kept, otherwise a re-upload would bring the address back.
Backups
The database is backed up daily, kept with rotation and verified by restoring it on a separate machine, not merely by the file existing.
Documents
The operator is sole trader Aleksei V. Tokarev. The personal data processing notification has been filed with Roskomnadzor; the registry number will appear in the policy once it is entered.