protobuf: Google's Data Serialization Standard as an Alternative to JSON

It is a mechanism for serializing structured data regardless of language or platform. It uses a binary format that is faster and more compact than the text-based JSON format, improving network transmission and storage efficiency.

It supports runtimes for major languages such as C++, Java, Python, Go, C#, Ruby, PHP, Dart, and JavaScript. Compiling a .proto file generates data structures usable with code in the corresponding language, allowing services written in different languages to exchange data using the same schema.

Unlike traditional approaches, it is designed to maintain backward compatibility even when the schema changes. Adding or removing fields does not break existing clients, and its extensible structure ensures long-term API stability.

It is frequently used in systems requiring RPC communication or large-scale data processing. It is particularly used as a data serialization layer in performance-critical backend services and mobile apps, and has been adopted as a standard in various internal Google systems.