Added fabric-medallion-architecture skill

[nielsvdc]

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• I have read and followed the Guidance for submissions involving paid services.
• My contribution adds a new instruction, prompt, agent, skill, or workflow file in the correct directory.
• The file follows the required naming convention.
• The content is clearly structured and follows the example format.
• I have tested my instructions, prompt, agent, skill, or workflow with GitHub Copilot.
• I have run npm start and verified that README.md is up to date.
• I am targeting the staged branch for this pull request.

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Description

Purpose

A prescriptive, decision-driven guide for designing data platforms using the medallion architecture pattern on Microsoft Fabric. This skill enables GitHub Copilot to provide targeted, context-aware guidance when users ask architecture or design questions about Fabric data projects.

What It Adds to awesome-copilot

This skill fills a gap in the awesome-copilot collection by offering:

• Structured decision rules for data engineers choosing between Lakehouse/Warehouse, layer boundaries, and storage organization
• Naming conventions that eliminate ambiguity (no jargon like fact_/dim_ prefixes that confuse non-technical consumers)
• Anti-patterns that teams commonly hit and need guidance to avoid
• Clear trigger phrases so Copilot surfaces this skill when users ask "which layer?", "where should this go?", or similar

Usage Context

Developers and data engineers building on Microsoft Fabric can ask Copilot questions like:

• "Should this table be bronze or silver?"
• "Do we need a separate landing zone?"
• "Lakehouse or Warehouse for our gold layer?"
• "How should I name this fact table?"

Copilot will invoke this skill and provide answers grounded in the medallion pattern rather than generic advice.

Audience

• Data platform architects and engineers on Fabric
• Teams standardizing data organization practices
• Anyone building analytics workloads on Microsoft Fabric

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Type of Contribution

• New instruction file.
• New prompt file.
• New agent file.
• New plugin.
• New skill file.
• New agentic workflow.
• Update to existing instruction, prompt, agent, plugin, skill, or workflow.
• Other (please specify):

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Additional Notes

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By submitting this pull request, I confirm that my contribution abides by the Code of Conduct and will be licensed under the MIT License.

[github-actions]

🔍 Skill Validator Results

⚠️ Warnings or advisories found

Scope	Checked
Skills	2
Agents	1
Total	3
Severity	Count
---	---:
❌ Errors	0
⚠️ Warnings	2
ℹ️ Advisories	0

Summary

Level	Finding
ℹ️	Found 2 skill(s)
ℹ️	[fabric-medallion-architecture] 📊 fabric-medallion-architecture: 5,413 BPE tokens [chars/4: 7,205] (comprehensive ✗), 25 sections, 4 code blocks
ℹ️	[fabric-medallion-architecture] ⚠ Skill is 5,413 BPE tokens (chars/4 estimate: 7,205) — "comprehensive" skills hurt performance by 2.9pp on average. Consider splitting into 2–3 focused skills.
ℹ️	[fabric-optimizations] 📊 fabric-optimizations: 1,349 BPE tokens [chars/4: 1,833] (detailed ✓), 12 sections, 0 code blocks
ℹ️	[fabric-optimizations] ⚠ No code blocks — agents perform better with concrete snippets and commands.
ℹ️	✅ All checks passed (2 skill(s))

Full validator output

```text Found 2 skill(s) [fabric-medallion-architecture] 📊 fabric-medallion-architecture: 5,413 BPE tokens [chars/4: 7,205] (comprehensive ✗), 25 sections, 4 code blocks [fabric-medallion-architecture] ⚠ Skill is 5,413 BPE tokens (chars/4 estimate: 7,205) — "comprehensive" skills hurt performance by 2.9pp on average. Consider splitting into 2–3 focused skills. [fabric-optimizations] 📊 fabric-optimizations: 1,349 BPE tokens [chars/4: 1,833] (detailed ✓), 12 sections, 0 code blocks [fabric-optimizations] ⚠ No code blocks — agents perform better with concrete snippets and commands. ✅ All checks passed (2 skill(s)) ```