Serialization

Serialization is the process of converting an in-memory object or data structure into a format that can be stored, transmitted, and subsequently reconstructed. Deserialization is the inverse operation. The serialized form may be textual, such as JSON, XML, or YAML, or binary, such as Protocol Buffers, MessagePack, Avro, Thrift, or BSON. Text formats are human-readable and typically easier to debug, while binary formats are often more compact and faster to parse.

Serialization serves several purposes: persistence to disk or databases, inter-process and inter-system communication, remote procedure calls, and data caching. It enables objects or data structures to survive program termination or transfer across machine boundaries.

Some formats are language-specific (for example, Java object serialization, Python pickle, or .NET binary serialization) and can package class metadata alongside data; others are language-agnostic (JSON, Protobuf, Avro) and designed for cross-language interoperability. Many modern systems use schema-based binary formats (Protobuf, Avro, Thrift) to enforce data contracts and enable efficient evolution.

Security and compatibility are important concerns. Deserialization can be vulnerable to remote code execution if untrusted input is accepted. Best practices include validating input, avoiding execution of code during deserialization, using explicit schemas, versioning data formats, and providing forward/backward compatibility guarantees.

Common use cases include REST APIs that return JSON, message queues that use binary formats for efficiency, and storage layers that persist serialized objects. Overall, serialization is a foundational technique in data exchange and persistence across software systems.