FDQF

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Developer Guide ​

Welcome to the Data Quality Framework developer documentation. This guide provides technical information for developers who want to understand, modify, or contribute to the framework.

Overview ​

The Data Quality Framework is a federated system designed to assess data quality at source while preserving privacy. It consists of two main components:

  • Data Quality Agent: Deployed at data sites to perform local quality assessments
  • Data Quality Server: Central coordinator that aggregates quality reports from multiple agents

The system implements a privacy-first architecture where raw data never leaves the source site. Only aggregated, differentially private quality metrics are shared with the central server.

Key Design Principles ​

  • Privacy by Design: Raw data remains at source; only privacy-protected aggregated metrics are shared
  • Federated Architecture: Distributed processing with central coordination
  • Extensible: Modular design supports multiple data sources and quality checks
  • Secure: Comprehensive security measures including signed container images and encrypted communication
  • Data Model Agnostic: Core architecture supports various data formats (currently focused on HL7 FHIR)

Technology Stack ​

Backend Technologies ​

  • Java 25
  • Spring Boot 3.5
  • SQLite
  • Maven

Frontend Technologies ​

  • Vue.js 3
  • Vue Router 4
  • Bootstrap 5
  • Bootstrap Icons
  • Axios
  • Vite

Infrastructure & DevOps ​

  • Docker
  • Docker Compose
  • GitHub Actions
  • Cosign
  • Codecov
  • OpenSSF Scorecard

Documentation ​

  • VitePress
  • Markdown

Security & Privacy ​

  • Differential Privacy
  • TLS/HTTPS
  • Spring Security
  • Signed Containers

Architecture Overview ​

System Architecture ​

┌─────────────────┐    ┌─────────────────┐    ┌─────────────────┐
│   Data Site A   │    │   Data Site B   │    │   Data Site C   │
│                 │    │                 │    │                 │
│ ┌─────────────┐ │    │ ┌─────────────┐ │    │ ┌─────────────┐ │
│ │    Agent    │ │    │ │    Agent    │ │    │ │    Agent    │ │
│ │             │ │    │ │             │ │    │ │             │ │
│ │  ┌───────┐  │ │    │ │  ┌───────┐  │ │    │ │  ┌───────┐  │ │
│ │  │ FHIR  │  │ │    │ │  │ FHIR  │  │ │    │ │  │ FHIR  │  │ │
│ │  │ Store │  │ │    │ │  │ Store │  │ │    │ │  │ Store │  │ │
│ │  └───────┘  │ │    │ │  └───────┘  │ │    │ │  └───────┘  │ │
│ └─────────────┘ │    │ └─────────────┘ │    │ └─────────────┘ │
└─────────────────┘    └─────────────────┘    └─────────────────┘
         │                       │                       │
         │ Privacy-protected     │ Privacy-protected     │ Privacy-protected
         │ quality metrics       │ quality metrics       │ quality metrics
         └───────────────────────┼───────────────────────┘
                                 │
                    ┌─────────────────────────┐
                    │  Data Quality Server    │
                    │                         │
                    │  ┌─────────────────┐    │
                    │  │   Aggregation   │    │
                    │  │   & Analysis    │    │
                    │  └─────────────────┘    │
                    │                         │
                    │  ┌─────────────────┐    │
                    │  │   Dashboard     │    │
                    │  │   & Reports     │    │
                    │  └─────────────────┘    │
                    └─────────────────────────┘

Agent Architecture ​

The Data Quality Agent follows a modular Spring Boot architecture:

  • Web Layer: Vue.js frontend + REST API controllers
  • Service Layer: Business logic and orchestration
  • Data Access Layer: JPA repositories and data persistence
  • External Integration: FHIR client and CQL query execution
  • Security Layer: Authentication, authorization, and differential privacy

Server Architecture ​

The Data Quality Server provides central coordination:

  • Agent Management: Registration and authentication of data quality agents
  • Report Aggregation: Collection and processing of quality reports
  • Dashboard: Multi-site quality visualization
  • API: RESTful endpoints for external integration

API Documentation ​

Both agent and server expose OpenAPI/Swagger documentation:

Documentation ​

The project documentation is built using VitePress, a modern static site generator that provides:

  • Hot Reload: Instant preview of documentation changes during development
  • Vue.js Integration: Custom components and interactive elements
  • Markdown-based: Easy-to-write documentation using standard Markdown
  • Built-in Features: Tips, warnings, code highlighting, and cross-references

For detailed information on contributing to documentation, see the Contributing Guide.