[eliasdejong]

The primary motivations were performance requirements and frustration with schema formats.

The ability to mutate serialized data allows for 2 things:

1) Services exchanging messages and making small changes each time e.g. adding a timestamp without full reserialization overhead.

2) A message producer can keep a message 'template' ready and only change the necessary fields each time before sending. As a result, serializing becomes practically free from a performance perspective.

[squirrellous]

Thanks. These are actually achievable with a custom protocol buffer implementation, but I agree at that point one may as well create a new format.

FWIW the other use case I was expecting is something like database queries where you’d select one particular column out of a json-like blob and want to avoid deserialization.