# ddd-by-examples/library

A comprehensive Domain-Driven Design example with problem space strategic analysis and various tactical patterns.

Repository: https://github.com/ddd-by-examples/library
Canonical: https://ross.abutalabs.com/products/library
Language: Java
License: MIT
License Family: permissive
Topics: domain-driven-design, ddd, ddd-architecture, c4, hexagonal-architecture, ports-and-adapters, crud, aggregate, aggregate-root, functions, vavr, archunit, spring, event-storming, events
Last push: 2023-07-07T21:43:17+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 2791, "days_push": 1153, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 5849, forks 831 (observed 2026-08-28T04:09:31.628377+00:00)

## What it is
A comprehensive example project demonstrating Domain-Driven Design (DDD) through a real-world library domain, including strategic analysis (event storming, C4 diagrams) and tactical patterns (aggregates, domain events, hexagonal architecture). It is a reference codebase for learning DDD in Java with Spring, Vavr, and ArchUnit.

## Use cases
- learn domain-driven design with a real codebase
- see how to model aggregates and domain events in Java
- understand hexagonal architecture / ports and adapters in practice
- study event storming and strategic DDD analysis
- find examples of testing domain logic with ArchUnit
- reference for structuring a Spring Boot DDD project

## When to choose
- you want a realistic, well-documented DDD example in Java
- you are teaching or learning tactical and strategic DDD patterns
- you need a reference for hexagonal architecture with Spring

## When to avoid
- you need a production-ready library management system
- you work outside the JVM/Spring ecosystem
- you want a framework or library to import rather than study

## Facets
- artifact type: learning-resource
- maturity: maintenance
- function: documentation, developer-tools, testing
- domain: tutorials, web-development, developer-tools
- platform: jvm
- tags: domain-driven-design, event-storming, hexagonal-architecture, ports-and-adapters, example-project, java, spring-boot, archunit, vavr, aggregate-design, ddd, spring

## Member repositories
- ddd-by-examples/library (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:31.628377+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:51:53.989637+00:00, confidence not recorded.
  - readme: https://github.com/ddd-by-examples/library (fetched 2026-08-28T04:09:31.628377+00:00, sha 57bf43117c45)
- Data as of 2026-08-30T08:39:29.467469+00:00.