AI & LLM Engineering for .NET Architects

Skills & Plugins: Extending the LLM with native C# functions

1 Views Updated 5/4/2026

AI Plugins & Native Code

An LLM is a thinker, not a doer. Plugins (formerly Skills) are the "Hands" of the AI. They allow the model to reach out and touch your database, your file system, or your internal APIs.

1. Semantic vs Native Plugins

  • Semantic Plugins: Prompts saved as code. Example: `RewriteToProfessional`.
  • Native Plugins: Real C# methods. Example: `GetStockPrice(string symbol)`.

2. The [KernelFunction] Attribute

To turn a C# method into a plugin, you just add an attribute.

[KernelFunction, Description("Fetches the weather for a city")]
public string GetWeather(string location) { ... }
The AI reads the **Description** to understand when it should call your function. Metadata is code!

4. Interview Mastery

Q: "What is 'Tool-Calling' and why is it better than simple text parsing?"

Architect Answer: "Tool-calling (or Function Calling) is when the LLM returns a structured JSON payload like `{ "function": "GetWeather", "args": { "location": "Dubai" } }` instead of just text. This is safer because the model has been trained specifically to output these parameters accurately. It allows for reliable integration between non-deterministic AI and deterministic C# business logic."

AI & LLM Engineering for .NET Architects
1. AI Foundations & Prompt Engineering
The LLM Landscape: Transformers, Attention, and Tokens Advanced Prompt Engineering: Few-shot, Chain-of-Thought, and ReAct Prompt Versioning & Management in Production LLM Cost Estimation: Token accounting and budget strategies
2. Semantic Kernel & Integration
Introduction to Microsoft Semantic Kernel (SK) Skills & Plugins: Extending the LLM with native C# functions Planner & Orchestration: Automating complex multi-step AI tasks Connectors: Switching between OpenAI, Azure OpenAI, and HuggingFace
3. Vector Databases & RAG
The RAG Pattern: Solving the 'Static Knowledge' problem Embeddings Deep Dive: Converting text to math Vector DBs: Azure AI Search vs Pinecode vs Milvus Hybrid Search: Combining Keyword and Semantic search for accuracy
4. Advanced RAG Techniques
Document Chunking Strategies: Overlap, Slidewindow, and Semantic splitting Recursive Document Processing for massive knowledge bases Context Window Management: Summarization vs Truncation Citations & Grounding: Ensuring the AI doesn't hallucinate
5. AI Safety & Guardrails
Content Moderation: Azure AI Content Safety integration Prompt Injection: Defending against adversarial attacks Punitiveness & Bias: Evaluating and mitigating model behavior Self-Correction Patterns: Letting the AI check its own work
6. Small Language Models (SLMs) & Local AI
The rise of SLMs: Phi-3, Llama-3-8B, and Mistral Running AI Locally with ONNX and LocalLLM Quantization: Running 70B models on 16GB RAM Edge AI: Deploying models to local devices and private clouds
7. Multimodal & Agentic AI
Multimodal AI: Processing Images, PDFs, and Audio in C# Agentic Workflows: Multi-agent collaboration with AutoGen Function Calling: Letting the LLM use your SQL and API tools Memory Management: Ephemeral vs Long-term Semantic memory
8. FAANG AI Engineer Interview
Case Study: Designing a Global Enterprise AI Knowledge Assistant Case Study: Building an Autonomous AI Agent for Software Dev