The protocol buffers approach is quite interesting. With proto3, there's basically no such thing as a "required" field anymore. All fields are now optional. No

The protocol buffers approach is quite interesting. With proto3, there's basically no such thing as a "required" field anymore. All fields are now optional. Now, being able to assert that a field is present in an object is a basic and valuable use-case for static typing. However, the developers felt that even this basic level of static type checking added too much friction whenever they had to update systems. https://capnproto.org/faq.html#how-do-i-make-a-field-required-like-in-protocol-buffers https://capnproto.org/faq.html#how-do-i-make-a-field-require...