What other interaction protocols/standards between systems do you know besides REST and SOAP?

In addition to REST and SOAP, there are other protocols and standards for system interaction:

• gRPC — a modern high-performance protocol from Google, using HTTP/2 and Protocol Buffers for serialization.
• GraphQL — a query language and runtime environment for APIs, allowing clients to request exactly the data they need.
• AMQP (Advanced Message Queuing Protocol) — a protocol for message exchange between systems, often used in message brokers.
• MQTT — a lightweight protocol for message transmission, often used in IoT.
• WebSocket — a protocol for bidirectional real-time communication between client and server.
• CORBA — a standard for object interaction in distributed systems.

Each of them is suitable for different scenarios depending on performance requirements, reliability, and data type.