Yes, of course i know. Now ICANN want $200K and 100,000,000 per year for maintenance and infrastructure
You’ll also need to have your own infrastructure at three different physical places of the world. All of these using Western (not Russian) wages level.
Though basically it will be ᴅɴꜱ servers using a relational database instead of a text file.
The relational database being connected to your website for registering databases.
It can be more difficult if you want to allow other registrars making register .blockchain domains.