We're using Nats (https://nats.io/ https://nats.io/) for event streaming and pub/sub. The sessions are aggregated in memory, then they go to Badger (https://git

We're using Nats (https://nats.io/ https://nats.io/) for event streaming and pub/sub. The sessions are aggregated in memory, then they go to Badger (https://github.com/dgraph-io/badger https://github.com/dgraph-io/badger), and finally the daily aggregates are easily distributable and immutable JSON files. We're setting a session identifier to sessionStorage and those id's are wiped out once the session is processed and leaves the server memory. We worked together with a privacy specialist to ensure this is not violating GDPR. Details on what/how we collect data is here: https://volument.com/privacy/ https://volument.com/privacy/