What are Data Contracts?

Establishing clear communication channels between the teams responsible for data sources and the team responsible for the data platform is paramount. This is where data contracts come into play.

Data contracts act as the bridge between source systems and data teams and are instrumental in upholding the integrity and reliability of data throughout the entire organization.

In this blog, we will delve into data contracts, focusing on the implementation strategies, best practices, and their crucial role in navigating a highly distributed and agile data ecosystem, specifically Data Vault.

What is a Data Contract?

A data contract is as a technical agreement between users of source systems and the data extraction team. It explicitly defines the structure and format of data exchanged through a data pipeline.

These are foundational in establishing a standardised data flows within an organisation. By providing a clear blueprint for data exchange, data contracts mitigate the risk of inconsistencies, errors, and misalignments, ensuring that data moves seamlessly through the pipeline in a controlled and structured manner.

As an example, the image below displays the map in which data flows throughout an organisation from the CRM through to the sales team report. With different teams requiring different data, data contracts provide every party guideline to follow when supplying and extracting data from the source system.

Why Use Data Contracts?

Data contracts act as guardians of interface quality, allowing for automated testing and governance structures to enforce adherence.

Beyond this, data contracts play a pivotal role in breaking down data silos by offering transparency into the data flow. They eliminate uncertainties and undocumented assumptions, ensuring that the data exchanged is not only accurate but also complete and consistent.

In essence, data contracts form the bedrock of strong data quality, emphasising precision in data ownership, scalability of distributed data architectures, and fostering a culture of collaborative feedback within the technical teams.

One of the benefits of standardising data contracts is that the source system data contract and validation can be standardised across many different consumers of that data. This reduces the need for the same validation tests to be developed multiple times.

Types of Data Contracts

A technical understanding of data contracts involves dissecting their types.

Timing Contracts

Timing contracts specify when data should be available for consumption within a data pipeline. The implementation of timing contracts demands precision in orchestrating data pipelines to meet specific timelines.

Quality Contracts

Quality contracts concentrate on the technical aspects of data accuracy, completeness, and consistency. These contracts set high standards for data quality, dictating technical specifications that the data must meet.

Schema Contracts

Schema contracts play a pivotal role in defining the structure and format of the data exchanged between source systems and the data team. They provide a detailed blueprint for data exchange, including the definition of data types, the relationships between different data elements, and any transformations or aggregations applied.

Format Contracts

Format contracts focus on the technical specifications of the data format, encompassing considerations such as file types, encoding, and data serialisation methods. These contracts dictate how data is represented and transmitted. For example, a format contract might specify that data should be exchanged in a particular file format (e.g., JSON, CSV) or using a specific encoding scheme.

Security Contracts

Security contracts outline the technical measures and protocols for securing sensitive data during transmission and storage. They involve specifying encryption standards, access controls, and authentication mechanisms.

Compliance Contracts

Compliance contracts address the technical requirements and standards necessary to meet regulatory and legal obligations. Compliance contracts involve adhering to standards and protocols mandated by regulatory bodies such as GDPR and CCPA. This may include implementing data retention policies, employing data masking techniques, and other technical measures to ensure that the organisation complies with relevant data protection and privacy regulations.

Data Contracts in a Data Vault

Within a Data Vault, data contracts take on increased significance. Acting as the adhesive that ensures the preservation of relationships between entities (Hubs, Links and Satellites), data contracts contribute substantially to maintaining the structural integrity of the Data Vault architecture.

This involves careful integration, ensuring that data contracts seamlessly align with the principles and design patterns of the Data Vault methodology.

When Should Data Contracts be Implemented?

The implementation of data contracts is pivotal under specific circumstances.

Organisations should prioritise data contracts when dealing with production pipelines, data products, or critical data assets where data reliability is non-negotiable.

Furthermore, the recurrence of data incidents stemming from unexpected schema changes signals a pressing need for robust data contracts that can safeguard against such technical challenges.

The Rise of Data Mesh and Data Contracts

Data mesh has gained popularity as a decentralised approach to data architecture, emphasising domain-oriented, autonomous data teams. Within data mesh, data contracts play a pivotal role as the technical enablers that facilitate seamless collaboration and integration across these distributed teams.

1. Decentralised Data Ownership

In a data mesh architecture, data ownership is distributed among various domain-oriented data teams. Each team is responsible for the data within their domain, and data contracts serve as the technical agreements that define how data is exchanged between these teams. This decentralised ownership model ensures that teams have autonomy over their data, and data contracts provide the technical boundaries within which this autonomy is exercised.

2. Centralised Data Governance

One of the keys to successful implementation of data mesh is providing a strong centralised governance function to oversee the management of data structures, including the use of data contracts.

3. Unison and Collaboration

Data contracts enables unity between different data domains within a data mesh. These contracts define the structure, format, and quality standards for data exchange, allowing diverse teams to collaborate seamlessly. The technical specifications outlined in data contracts ensure that data produced by one team aligns with the expectations and requirements of other teams, fostering a cohesive data ecosystem.

4. Technical Standardisation

Within a data mesh, ensuring consistency in data quality and format across diverse domains is a formidable technical challenge. Data contracts address this challenge by establishing technical standards that all participating teams adhere to. This standardisation is essential for maintaining a coherent and reliable data landscape, and data contracts serve as the technical governance framework that upholds these standards.

5. Evolutionary Data Architecture

The nature of data mesh encourages an evolutionary approach to data architecture. As business requirements and data domains evolve, so must the technical specifications for data exchange. Data contracts, within this context, support an iterative and adaptive technical framework. Teams can evolve their data contracts to accommodate changing business needs while maintaining technical compatibility and adherence to quality standards.

6. Technical Infrastructure for Data Products

Data mesh promotes the creation of data products by domain-oriented data teams. These data products often serve as the technical artifacts exchanged between teams. Data contracts define the technical expectations and specifications for these data products, ensuring that they meet the required quality, format, and timing standards. This technical infrastructure supports the creation, exchange, and consumption of data products within the data mesh architecture.

Conclusion

In the realm of data engineering, where precision and technical acumen are paramount, mastering data contracts within the Data Vault framework is imperative.

This blog has provided an overview of the role played by data contracts, from technical agreements to their seamless integration into sound business practice and the broader landscape of data mesh. As data engineering continues to evolve, the mastery of data contracts stands will give organisations increased effectiveness and data reliability.