Greetings from DK !
Thought I wanted to share some output from my Bachelors thesis which showcases a nice use case for Vaadin, in my opinion at least.
I created something called a LoRaWAN Join Server. It has to do with the derivation of session keys for devices in a network to encrypt and integrity check data with. These keys are derived from long lived root keys (up to 15 years), which need to be stored in a quite secure manner. For this, I used Key Stores from Bouncy Castle in such a way that owners of devices have direct ownership to the devices via passwords.
I used Vaadin flow as the UI framework, since it fits right into the use case. Everything critical/sensitive happens server-side in a secure environment and no need to expose a management REST API if one doesn’t need to (even though it is exposed by default as-is 
).
There is of course plenty of flaws and the solution is definitely not secure enough at the moment.
Anyways, go check it out if it sparks some interest! 
