RudderStack describes itself as a customer data platform for collecting, unifying and activating customer data. It offers SDKs for web, mobile and server-side sources plus webhooks, in-flight transformations that can mask personal data, identity resolution into an identity graph in the customer's own data warehouse, and delivery of data to many downstream destinations. It also provides schema management, event validation and consent automation. It is delivered as a RudderStack-hosted cloud service or self-hosted through the rudder-server backend, which runs on Docker or Kubernetes and depends on PostgreSQL.
RudderStack Inc. is a US company, and the vendor states that it does not store your data. For RudderStack-hosted workspaces the data plane runs in a chosen region, US or EU, and event data is processed and stored in that same region. The rudder-server source code is public but released under the Elastic License 2.0, which is source-available rather than an open source licence. Self-hosting lets a European organisation keep processing in its own cloud or on-premises environment.