Hi @Samuel Stütz​ , the implementation of Spark on GCP is over Kubernetes so yes the configuration is a different as compared to Databricks over Azure/AWS. But for security purposes we do recommend being careful with the firewalls. As @Kaniz Fatma​  shared please refer to the security guidelines for GCP here. For a properly configured cluster, the Spark UI should be accessible but through a SSH tunnel.

If you can share more details such as what job are you running, more screenshots of the issue and steps to reproduce the issue. Someone here should be able to help you out!!