data-contract-mesh

What You'll Build

A comprehensive data contract system that acts like unit tests for your data pipelines. Before any team can change their data schema, your system validates that it won't break downstream consumers. This prevents the #1 cause of data outages - unexpected schema changes.

Why This Project Matters

• Solve Industry Pain: Schema changes cause 60% of data pipeline failures
• Enterprise Scale: Fortune 500 companies are adopting data contracts
• Team Collaboration: Enable 100+ teams to share data safely

Tech Stack Explained for Beginners

Technology	What it is	Why you'll use it
Pact	Contract testing framework	Validates that data producers match consumer expectations
Pydantic	Python data validation library	Enforces data types and constraints at runtime
OpenMetadata	Open-source data catalog	Central registry for all contracts and lineage
Apache Airflow	Workflow orchestrator	Runs contract validation on schedule
DataHub	Metadata platform	Tracks contract versions and compliance
LakeFS	Version control for data	Allows testing schema changes in isolation

Step-by-Step Build Plan

1. Week 1: Design contract schema and set up OpenMetadata
2. Week 2: Build Pydantic models for common data types
3. Week 3: Implement contract validation framework
4. Week 4: Create CI/CD integration for automatic checking
5. Week 5: Build contract registry and discovery UI
6. Week 6: Add versioning and migration tools
7. Week 7: Implement monitoring and compliance reporting

Detailed Requirements

Functional Requirements

• Contract Definition:
  • Support JSON Schema and Protobuf formats
  • Define required/optional fields
  • Specify data types and constraints
  • Document field meanings and examples
  • Version contracts with semantic versioning
• Validation Pipeline:
  • Check every data pipeline against contracts
  • Validate both schema and data quality rules
  • Support backward compatibility checking
  • Generate migration guides for changes
• Developer Experience:
  • CLI tool for contract creation
  • VS Code extension for validation
  • Auto-generate code from contracts
  • Contract testing in CI/CD

Technical Requirements

• Coverage Goals:
  • 99% of production tables under contract
  • Validate 1M+ records/day
  • Support 10+ data platforms
  • Handle 1000+ contract versions
• Performance:
  • Contract validation < 10 seconds
  • Catalog search < 500ms
  • CI/CD checks < 2 minutes
  • Real-time violation alerts
• Governance:
  • Audit trail for all changes
  • Approval workflow for breaking changes
  • Compliance reporting dashboard
  • SLA monitoring per contract

Prerequisites & Learning Path

• Required: Python, SQL, understanding of APIs and schemas
• Helpful: Experience with data quality issues
• You'll Learn: Data governance, contract testing, metadata management

Success Metrics

• Achieve 99% contract coverage
• Reduce schema-related incidents by 90%
• Detect violations within 10 minutes
• Zero breaking changes reach production
• Onboard 50+ data producers