Mastering Domain-Driven Design

Differentiate between Core, Supporting, and Generic subdomains in a business context.

Identify and categorize the subdomains within a SaaS billing and ledger business model.

Define Bounded Contexts by identifying the linguistic boundaries where business terms have different meanings.

Draw a Context Map illustrating standard patterns (e.g., Partnership, Shared Kernel, Customer/Supplier) to establish integration relationships.

Analyze integration requirements to justify the selection of the Anticorruption Layer (ACL) pattern.

Contrast the Anticorruption Layer (ACL) with Conformist and Open Host Service patterns.

Design an Anticorruption Layer in Go to securely integrate an internal billing context with a legacy external payment gateway.

Distinguish between Value Objects and Entities within a domain model.

Implement immutable Value Objects in Go using structs and custom types (e.g., Money, Currency).

Implement rich Entities in Go that protect their invariants by exposing behavior rather than state.

Write unit tests in Go to strictly validate the business behavior of Value Objects and Entities.

Define the concept of an Aggregate and an Aggregate Root.

Design transactional consistency boundaries using Aggregates for a Subscription model.

Implement a Subscription Aggregate Root in Go that strictly enforces business invariants.

Design Aggregate references using IDs rather than direct object references in Go structs.

Implement a Factory in Go to encapsulate the creation logic and initial validation of a new Subscription Aggregate.

Identify when to use a Domain Service for logic that spans multiple Aggregates.

Implement a Domain Service in Go to encapsulate cross-aggregate business rules, such as currency conversion.

Define the Repository pattern and its purpose in persisting Aggregate Roots.

Define Repository interfaces within the domain layer to decouple business logic from infrastructure.

Implement an in-memory Repository in Go to facilitate isolated testing of domain logic.

Explain the principles of Hexagonal Architecture (Ports and Adapters) for isolating the domain.

Differentiate Application Services from Domain Services.

Implement Application Services in Go to orchestrate domain use cases (e.g., processing a subscription cancellation).

Structure a Go project using Hexagonal Architecture principles to separate domain, application, and infrastructure layers.

Implement a PostgreSQL-backed Repository adapter in Go, managing transactions aligned with Aggregate boundaries.

Implement a REST API adapter using a Go web framework to trigger Application Service methods.

Define Domain Events and their critical role in decoupling Bounded Contexts.

Model Domain Events as explicit Go structs (e.g., SubscriptionCanceled, PaymentFailed).

Implement an in-memory event dispatcher in Go to publish and subscribe to Domain Events within a single process.

Handle a Domain Event in a separate Application Service to trigger localized side effects.

Identify the architectural role of asynchronous messaging to decouple Bounded Contexts in a distributed system.

Implement an Event Publisher adapter in Go integrating with a message broker (e.g., RabbitMQ or Kafka).

Implement an Event Subscriber worker in Go to process messages in a downstream Ledger context.

Explain the trade-offs of eventual consistency and its impact on user experience.

Implement an idempotent message consumer in Go to safely handle duplicate event delivery.

Implement a retry mechanism with a dead-letter queue (DLQ) strategy in a Go event subscriber.

Explain the Command Query Responsibility Segregation (CQRS) pattern and its benefits.

Design distinct 'write' (command) and 'read' (query) models for a specific use case.

Implement a command handler in Go to process a command that modifies state.

Implement a query handler in Go that reads directly from a simplified 'read' model.

Use a Domain Event to update the 'read' model after a command has been successfully processed.

Define the strategic role and boundaries of a new 'Invoicing' Bounded Context.

Model the core Aggregates, Entities, and Value Objects for the 'Invoicing' context based on its Ubiquitous Language.

Implement the Invoice Aggregate Root in Go, incorporating Value Objects and enforcing all business invariants.

Identify and publish a relevant Domain Event (e.g., 'SubscriptionRenewed') from the Subscription context.

Implement an event subscriber in the Invoicing context's infrastructure layer to consume the Domain Event.

Implement the application logic in the Invoicing context to process the consumed event and trigger the creation of a new invoice.

Execute and trace an end-to-end test scenario, verifying state changes and event-driven communication across the 'Invoicing' and 'Subscription' contexts.

Create a personal checklist summarizing key strategic and tactical DDD principles learned throughout the course.

Apply the checklist to audit the strategic design (Context Map) and tactical design (Aggregates) of the capstone project.

Compose a summary identifying one major strength and one area for future improvement in the project's adherence to DDD principles.