These are arc42 documentations we cannot host, usually because their licence does not allow it. We link them because we consider them useful or interesting. We have not checked their structure and content. That is the difference between this page and the examples.
Ordered roughly easiest first. Start at the top if arc42 is new to you, otherwise skip to Deep and finished. Every note is ours, and dated.
Start here
Short, self-contained, and readable in one sitting. If you have never seen a complete arc42 document, open one of these first.
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Invented subject · Sections: All 12
Star Wars Death Star arc42 Documentation
Juan G. Carmona Published at github.com
Markdown · Mermaid diagrams
The battle station from Star Wars, documented as if it were a system under construction — an invented subject used to walk through the arc42 template end to end, not a system anyone operates.
Read it for the shape of the template rather than for depth: roughly 5,000 words across all twelve sections, largely bullet lists, and the subject matter means no section has to survive contact with a real constraint. What it does teach well is traceability. Section 9 records the single central reactor as a decision, states the single point of failure in the rationale, and hands it forward to section 11, where it reappears as risk R1 with a mitigation — the decision-to-risk chain that real documentation usually leaves for the reader to reconstruct. Every diagram is Mermaid inside the Markdown, so GitHub renders them in place and there is nothing to check out or build.
Added 2026-08
- Sections
- All 12
- Licence
- CC BY-NC 4.0
- Language
- English and Spanish
- Written
- 2024–2025
Real systems, real compromises
Documentation of software somebody has to keep running. Expect the template to have been bent, and expect gaps where it met a deadline.
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Production system · Sections: All 12
Atlassian Tools — Architecture Documentation
Andreas Huber Published at huber-and.github.io
Antora · AsciiDoc · PlantUML diagrams · Confluence Cloud publishing · 16 quality scenarios
Documentation of a Maven plugin and two Java libraries that publish Antora-generated documentation to Confluence Cloud — for teams that write docs as AsciiDoc but need them visible to colleagues who only look in Confluence. Twelve arc42 chapters, self-published by the tool it describes to both this site and a live Confluence space.
- Sections
- All 12
- Licence
- Apache-2.0
- Language
- English
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Production system · Sections: All 12
Heldenhelfer
smart and public GmbH, for Smarte Region Würzburg Published at gitlab.opencode.de
Public sector · AsciiDoc · Structurizr diagrams · 35 quality scenarios · 7 decision records
A volunteering platform for the clubs and initiatives of Würzburg: a self-built portal for club records and membership, wired by Kafka events to a Nextcloud digital office and a Discourse forum, with Keycloak single sign-on across all three.
“Heldenhelfer liefert Euch alle Werkzeuge für moderne und effiziente Vereinsarbeit.” Mit Heldenhelfer bieten Stadt und Landkreis Würzburg eine Plattform, die ehrenamtlichen Strukturen wie Vereinen dabei hilft, sich intern besser zu organisieren, mit anderen zu vernetzen und sich öffentlich zu präsentieren. Für engagierte Bürger:innen dient sie als zentrale Anlaufstelle, um Termine, Kontakte und Aktionen von Vereinen und Initiativen zu entdecken.
Development on this codebase stopped in August 2024 and the repository is archived; the live platform now runs at heldenhelfer.wuerzburg.de.
Added 2026-08
- Sections
- All 12
- Licence
- MIT
- Language
- English
- Written
- 2024
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Production system · Sections: All but 4 and 9
geOrchestra Gateway — Architecture Documentation
The geOrchestra project Published at docs.georchestra.org
Gateway component only · C4 section structure · Markdown · Structurizr diagrams
The authentication gateway of geOrchestra, an open-source spatial data infrastructure run largely by public bodies: A Spring Cloud Gateway specialisation that fronts every other service in the platform and handles login, authorisation and routing for all of them.
The documentation lives in the gateway’s own repository and is released with it, which is the first thing worth noticing: it is maintained as code, not as a deliverable. Every diagram is generated from a checked-in Structurizr model with a build script beside it, so the pictures cannot quietly drift away from the prose. The scope: One component of geOrchestra, not the platform, and the longest sections are quality requirements and risks.
Added 2026-08
- Sections
- All but 4 and 9
- Licence
- GPL-3.0
- Language
- English
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Production system · Sections: All but 6, 10 and 11
GA-Lotse
The GA-Lotse project Published at gitlab.opencode.de
Public sector · AsciiDoc · 7 decision records
The single application Hesse's public health offices use for their statutory casework, e.g. school entry examinations, measles vaccination checks, hygiene inspections of facilities and travel medicine, with an online route through which citizens reach the office directly.
The service mesh record explains why the team built their own instead of taking Istio or Linkerd. then writes down plainly that the choice buys them more testing, more security review and more maintenance. The original documentation sits on openCode, the German public sector Platform for Digital Sovereignty. (Don’t confuse with the opencode.ai coding agent of same name)
Added 2026-08
- Sections
- All but 6, 10 and 11
- Licence
- CC BY-SA 4.0
- Language
- English
- Written
- 2024–2025
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Production system · Sections: All 12
Urbo — Smart City Platform
SWCode, for Stadt Soest Published at gitlab.opencode.de
Public sector · Markdown · Mermaid diagrams · 11 decision records · Single file
The Urbo smart city platform as it runs for the city of Soest: A Kotlin modular monolith with an Angular citizen app and a CMS, into which a city switches on modules for news, waste collection, parking, construction sites and citizen participation.
Urbo is built and maintained by SWCode, a software house in Soest, and published by the city on openCode, the German public sector’s Platform for Digital Sovereignty. (Not to be confused with the opencode.ai coding agent of the same name.) It began as the SoestApp, part of a federally funded smart city model project, and now runs for Bamberg and Wesel as well.
Added 2026-08
- Project site
- urbo.digital
- Developer
- swcode.io
- Sections
- All 12
- Licence
- EUPL-1.2
- Language
- English
- Written
- 2024–2026
Corpora
Not one documentation but many. You have to pick a team before you can read anything, and the sample size is the whole point.
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Student coursework · Sections: Varies by team
Software Architecture course, University of Oviedo
Students of the Software Engineering degree, University of Oviedo Published at arquisoft.github.io
~25 new documentations a year · AsciiDoc · Spanish and English cohorts
Not one documentation but several hundred: every team on this course documents the web application it builds over the semester using arc42 and publishes it, roughly twenty-five new ones a year since 2018, in Spanish and English cohorts working to the same brief.
Read this one as coursework and it will not disappoint you. It is written by undergraduates in the second semester of their third year, under deadline, about systems that live for one term. Nothing here has been maintained, operated, or argued over by anyone who had to live with the consequences. What no other link on this page can offer is the sample size: Twenty-five teams document the same brief in the same template in the same semester, which turns the template itself into the subject: the sections everybody fills in usefully and the ones everybody pads are visible at a glance, and that is a genuinely useful thing to see before you write your own. Start from the course page, pick a year, then pick a team. The 2025-26 cohort is
yovi, and yovi_en3a is a representative one.Added 2026-08
- Sections
- Varies by team
- Licence
- not stated
- Language
- English and Spanish
- Written
- 2018–2026
Deep and finished
Every section filled and argued. The longest reads on this page, and the ones to arrive at rather than to start with.
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Invented subject · Sections: All 12
DokChess
Stefan Zörner Published at dokchess.de
Java
A chess engine in Java, written so that its architecture could be documented: Published in full as a browsable arc42 site.
This is what a finished (and polished) arc42 documentation looks like.
Added 2026-08
- Sections
- All 12
- Licence
- CC BY-NC-SA
- Language
- German, with an English translation
- Written
- 2025