NAV handles a lot of applications for our benefits(sickness, unemployment etc.). We are rewriting the systems handling these applications to a stream based approach, placing Kafka-streams in the centre of our architecture. This talk will go through our approach to building these systems. We are mostly using Kotling as our programming language, and are running our applications on Kubernetes. We use Change-data-capture to extract data from our legacy systems, to ease the pain of migration. By treating our data, and our applications as streams we get a lot of benefits. We can rerun our applications with different rules, to simulate the effect of policy changes. We can do real time evaluation of applications, to improve the user experience. We also get better robustness, as we remove the runtime dependency to our core systems, and can receive applications even when other parts of the systems are down. The talk will also present the architecural rules we are implementing for NAV, using streams as the main communication pattern between organization units, and some learnings from our current work on a data platform to support Life is a stream of events.