Add dotnet-software-architect skill

[diazvaldiviav]

Summary

Adds dotnet-software-architect, a skill that acts as a senior C#/.NET software architect for designing, structuring, and reviewing ASP.NET Core, EF Core, Aspire, Blazor, and worker-service codebases.

It triggers on requests like "how should I structure this .NET solution", "clean, layered, modular monolith, or microservices?", "review this solution's architecture", or "write an ADR" — and on pasted .csproj/.sln files or namespace skeletons where the real question is about boundaries and dependencies.

What it does

The skill guides Claude through a six-step workflow:

1. Understand the driving forces before proposing any structure.
2. Choose an architectural style deliberately — the honest default is a layered modular monolith, not microservices or full DDD.
3. Propose a concrete solution and project layout with an enforced dependency direction.
4. Apply evidence-backed patterns.
5. Make trade-offs and risks explicit.
6. Record the decision as an ADR.

Its non-negotiable principles: dependencies point inward, the domain stays rich and infrastructure dumb, boundaries are enforced by the compiler plus architecture tests (NetArchTest / ArchUnitNET), don't prematurely distribute, and match ceremony to complexity.

Contents

Seven files, 1,081 lines, all additions:

• SKILL.md (131 lines)
• references/decision-guide.md — choosing an architectural style
• references/pattern-catalog.md — 366 lines of evidence-backed patterns
• references/project-structures.md — concrete solution/project trees
• references/review-checklist.md — architectural review pass
• references/adr-template.md — ADR format
• LICENSE.txt — Apache 2.0

Plus one line in .claude-plugin/marketplace.json registering it under the example-skills plugin, in alphabetical position.

The reference files load on demand rather than up front, following the pattern used by mcp-builder and skill-creator.

Grounding

Patterns are drawn from public reference codebases rather than invented: modular-monolith-with-DDD, the Jason Taylor and Ardalis Clean Architecture templates, and Microsoft's eShop / eShopOnWeb. The domain examples in the reference files (Acme.Billing.sln, an Invoice aggregate) are deliberately generic.

Conventions followed

• Folder name matches the frontmatter name field.
• Frontmatter carries license: Complete terms in LICENSE.txt, matching the other skills.
• No existing skill or file is modified except the single added line in marketplace.json.

A question for the maintainers

There is no CONTRIBUTING.md in this repository, so it isn't clear whether community-authored skills are welcome here. Are you accepting skill contributions from outside Anthropic? If not, I'm happy to close this and publish it as a separate marketplace instead — no hard feelings, and it'd be useful to say so in a CONTRIBUTING.md for the next person.

If you are, I have a companion skill (scrum-master-planner) I'd submit as a separate PR.

Licensed Apache 2.0, copyright retained by the author.