The nameservers point to Epik, so at least the DNS is run by them. The actual host is behind ddos-guard, so they may/may not be hosting the data with them or another provider.
As Epik seems to focus on shared hosting, and LAMP stack style applications and parler was using a proprietary DB in the last offering, they might reasonably have the actual hosting somewhere else.
Scylla Enterprise [0] [1], which is a Cassandra-compatible NoSQL database, though I think that they were probably using the DynamoDB API shim to talk to it. The non-enterprise version is open source, but fewer features.
As Epik seems to focus on shared hosting, and LAMP stack style applications and parler was using a proprietary DB in the last offering, they might reasonably have the actual hosting somewhere else.
Edit: Typo