Use the open-source free `ArchUnitNET` library for architecture rules in .NET tests.
.NET Architecture
Design or review .NET solution architecture across modular monoliths, clean architecture, vertical slices, microservices, DDD, CQRS, and cloud-native boundaries without over-engineering. USE FOR: .NET architecture choices; layer and domain boundary review; service decomposition; clean architecture, vertical slice, DDD, CQRS, and modular monolith decisions. DO NOT USE FOR: unrelated stacks; generic tasks that do not need this specific guidance. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.
Trigger On
- choosing architecture for a new or evolving .NET system
- reviewing layer boundaries, domain boundaries, or service decomposition
- deciding whether clean architecture, vertical slices, CQRS, or microservices are justified
Workflow
- Start from business capability boundaries and change frequency, not from a preferred diagram style.
- Use simple modular monolith patterns by default, and move to microservices only when team autonomy, scale, or deployment boundaries justify the added operational cost.
- Apply DDD and CQRS where business rules are genuinely complex; avoid forcing aggregates and command pipelines into CRUD-heavy code with no payoff.
- Keep dependencies flowing inward when using clean architecture, but avoid creating extra projects that add ceremony without ownership clarity.
- Make integration boundaries explicit: contracts, storage ownership, messaging, consistency model, and observability expectations.
- Use
aspirewhen local orchestration, service discovery, and developer observability are part of the architecture story.
Deliver
- an architecture direction that matches system complexity
- clear project and dependency boundaries
- migration notes or tradeoffs when changing an existing structure
Validate
- the proposed structure reduces rather than increases accidental complexity
- data ownership and integration paths are explicit
- the architecture is testable and operable, not just diagram-friendly
References
- references/patterns.md - detailed implementations of Clean Architecture, Vertical Slices, DDD, CQRS, Modular Monolith, and Microservices with C# 12+ examples
- references/anti-patterns.md - common architectural mistakes including over-abstraction, anemic domain models, premature microservices, and cargo cult patterns
Related skills
Use the open-source free `NetArchTest.Rules` library for architecture rules in .NET unit tests.
Use `graphify-dotnet` to generate codebase knowledge graphs, architecture snapshots, and exportable repository maps from .NET or polyglot source trees, with optional AI-enriched…
Related agents
.NET Router
Broad .NET triage agent that classifies the repo and routes work to the right skills or specialist agents.
Also works: dotnet agents install router