I disagree severely with large swaths of this article. The biggest problem is here: >Of course, the actual serialization logic is allowed to do something smart

I disagree severely with large swaths of this article. The biggest problem is here: >Of course, the actual serialization logic is allowed to do something smarter than pushing linked-lists across the network---after all, implementations and semantics don't need to align one-to-one. I like that I can read a pb dump in hex and have it map quite closely to the protocol definition, rather than being viewed through heaping piles of abstractions. This is only going to make it more confusing and more work to use, with the only gain being to make some functional programmer feel squishy about their beautiful type system. I largely agree with the "The Lie of Backwards- and Forwards-Compatibility" section. You can feed /dev/urandom into nearly any protobuf definition and it'll happily give you nonsense back, no errors. I understand why this is the case, and I'm not sure it should change, but it's bitten me several times.