DataContracts

DataContracts are formal agreements between data producers and data consumers that specify what data is produced, how it is formatted, when it is delivered, and the quality and semantics expected from the data. They serve as a contract for interoperability in data pipelines, data marketplaces, and analytics platforms, helping teams coordinate changes and reduce surprises when data flows between systems.

Typical components of a DataContract include the data schema (fields, data types, nullability, and nesting), data formats (JSON, Parquet, Avro, etc.), and the semantics of each field (units, business meaning). They also outline data quality rules (valid ranges, completeness, timeliness), delivery cadence and latency expectations, and delivery guarantees (for example, at-least-once or exactly-once processing). Versioning and compatibility rules specify how schemas may evolve over time, along with notice periods for breaking changes. Metadata such as lineage, ownership, and security or privacy constraints are commonly included.

Lifecycle and enforcement involve publishing and versioning contracts, validating data against the contract, and monitoring for violations or drift. Enforcement can be automated through schema registries, contract tests, data quality checks, and observability dashboards. When violations occur, teams renegotiate or adjust the contract, balancing forward and backward compatibility.

DataContracts are used across batch and streaming pipelines, data lakes, data warehouses, and data services. They improve clarity, reliability, and governance, but require coordination, tooling, and ongoing management to handle evolving data schemas and quality expectations. They are related to, but distinct from, data catalogs, schema registries, and API contract practices.