The IoT/IIoT world has a data model problem and the concept of Digital Twin has made this issue more important. Plenty of people have tried to fix it. RFC 9880 and its Semantic Definition Format (SDF) are a serious attempt: a JSON-based, ecosystem-neutral way to describe what a device is and what it does. I have had some experiences with this specification, and I’ve understood that the format shows its full value once you treat it as source code, something you compile.[…​]

In Part 1, the minimal deployment showed constraints traveling with the proxy: authentication, encryption, hardened deserialization, all declared in configuration and enforced at the call boundary. The proxy is a JAR. That JAR was downloaded and unmarshalled before any constraint ran. That step is the earlier problem. Distributed Java systems that load remote code are vulnerable to supply chain compromise: an attacker can replace a legitimate JAR with one containing malicious bytecode.[…​]

I keep coming back to java.util.ServiceLoader. I have used it to put a JSON layer behind a contract, so the core code carries no direct dependency on any particular JSON library, and I can swap the implementation without touching callers. The same shape works for JWT handling, where the concrete library might be jose4j or another JOSE implementation, and you can easily find other decoupling use-cases.[…​]