Applies layered n-tier architecture with enforced boundaries.
SkillScore95Maintained
Automatic
◆Coding pack
Last verified 8/21/2026
What it changes
Passed 21 of 22 test cases with the skill, and 16 of 22 without it.
Without skill73%
With skill95%
Checks it passed that the model alone missed
Specifies the layer sequence UI to Controller to Service to Domain to Persistence
Requires a committed formal dependency diagram matching the documented layer boundaries
Recommends strict top-down layer dependencies rather than dependency inversion interfaces
and 4 more in the full report
5 fixed16 passed either way1 still failing0 broke
Pass-rate lift
+23 pp
Tokens
+24%
Agent turns
0%
Response time
-23%
Model gemini-3.6-flashMeasured 8/21/2026v1 · latest is v221 of 22 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
This benchmark measured an earlier version of the skill.
See it in action
One of 5 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 5
Prompt
What documentation artifacts must be committed and verified as exit criteria before approving our N-tier architectural rollout?
What was checked, without and with the skill
Checked
Without skill
With skill
Requires an Architecture Decision Record documenting chosen layer stack and dependency rules
Missed
Passed
Requires a committed formal dependency diagram matching the documented layer boundaries
Missed
Passed
case-15 · gemini-3.6-flash · 8/21/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md82 linessingle file
The Layered (N-Tier) Architecture Paradigm
When to Employ This Paradigm
When teams need clear architectural boundaries and a familiar structure for moderate-sized systems.
When compliance or operations teams require clear separation of concerns (e.g., UI vs. domain logic vs. persistence).
When the deployment artifact remains a monolith, but code clarity and separation are degrading.
When NOT To Use This Paradigm
When high scalability demands require independent scaling of components
When multiple teams need independent deployment cycles
When complex business logic requires frequent cross-layer communication
When microservices architecture is already planned or in place
When real-time processing requirements make layered communication too slow
Adoption Steps
Define the Layers: Establish a clear set of layers. A common stack includes: Presentation -> Application/Service -> Domain -> Data Access.
Enforce Dependency Direction: Code in a given layer may only depend on the layer immediately below it. Forbid any "upward" dependencies or imports.
Centralize Cross-Cutting Concerns: Implement concerns like logging, authentication, and validation as centralized middleware or policies, rather than duplicating this logic in each layer.
Test Each Layer Appropriately: Apply testing strategies suitable for each layer, such as unit tests for the domain layer, service-layer tests for orchestration logic, and integration tests for persistence adapters.
Document and Enforce Interactions: Maintain up-to-date dependency diagrams and use automated architecture tests to prevent developers from creating "shortcut" dependencies that violate the layering rules.
Key Deliverables
An Architecture Decision Record (ADR) that captures the responsibilities of each layer, the allowed dependencies between them, and the policy for any exceptions.
A formal dependency diagram stored with the project documentation.
Automated architectural checks (e.g., using ArchUnit, dep-cruise, or custom scripts) to prevent rule violations from being merged.