Domain-Driven Design Practice in Lead Management System: From Theory to Implementation

This article demonstrates how to apply Domain-Driven Design (DDD) methodology to build a lead management system in the education domain. The education sector workflow includes: student recruitment, lead management, educational administration, student management, interactive learning support, and reputation building. The lead management system serves as a critical bridge connecting student recruitment with educational administration.

The article first explains why DDD is needed: traditional database-driven design creates data models without behavior, resulting in process-oriented thinking. DDD enables building an object-oriented system with proper domain modeling.

The core content covers three main areas:

1. DDD Standard Four-Layer Architecture: Infrastructure Layer (persistence capabilities using repositories for databases like MySQL, HBase, MongoDB, ES), Domain Layer (core business logic containing domain models and domain services - entities and value objects), Application Layer (business use case orchestration), and User Interface Layer (data presentation and command handling).

2. Four-Color Prototype Analysis: A requirement analysis technique using four archetypes - Moment-Interval (MI, pink) for time-based activities, Part-Place-Thing (PPT, green) for participants and objects, Description (DESC, blue) for common attributes, and Role (yellow) for identities. The summary formula: "A what kind of person or object with what role participates in an activity at a certain time or period at a certain location."

3. Core DDD Concepts: Entities (with unique identity and mutable attributes), Value Objects (immutable, compared by internal values), Aggregates (cohesive domain object collections with aggregate roots), and Repositories (bridging domain and infrastructure layers, storing aggregates).

The practical section applies these concepts to the lead management domain, identifying entities (ClueEntity, SourceEntity, TagEntity, RecordEntity, UserEntity), defining aggregates and aggregate roots, and designing corresponding repositories (ClueRepository, SourceRepository, TagRepository, RecordRepository).