1.4 - AI App Architecture
Today we explore AI application architecture in detail, learning to identify resources and understand how components work together to create intelligent applications.
What You’ll Learn
Section titled “What You’ll Learn”- Common patterns in AI application architecture
- How to identify and categorize Azure resources in an architecture diagram
- The Retrieval Augmented Generation (RAG) pattern
- How data flows through an AI application
Resources
Section titled “Resources”Before diving in, review these resources:
- 📘 Azure OpenAI Architecture Patterns - Baseline architecture for OpenAI applications
- 📘 RAG Pattern Guide - Comprehensive RAG implementation guide
- 🔗 Azure Architecture Center - AI - Collection of AI architecture patterns
Anatomy of an AI Application
Section titled “Anatomy of an AI Application”Let’s deconstruct a typical AI application architecture into its key components:
1. User Interface Layer
Section titled “1. User Interface Layer”Purpose: How users interact with your application
Common Azure Services:
- Azure Static Web Apps: For React/Angular/Vue frontends
- Azure App Service: For server-rendered applications
- Azure Container Apps: For containerized frontends
What it Does:
- Renders UI
- Captures user input
- Displays AI responses
- Manages session state
2. API & Gateway Layer
Section titled “2. API & Gateway Layer”Purpose: Entry point and traffic management
Common Azure Services:
- Azure API Management: Full-featured API gateway
- Azure Application Gateway: Load balancing with WAF
- Azure Front Door: Global routing and CDN
What it Does:
- Rate limiting
- Authentication/Authorization
- Request routing
- Caching
- Monitoring
3. Application Logic Layer
Section titled “3. Application Logic Layer”Purpose: Business logic and orchestration
Common Azure Services:
- Azure Functions: Event-driven, serverless compute
- Azure Container Apps: Containerized microservices
- Azure App Service: Full web application hosting
- Azure Kubernetes Service (AKS): Enterprise container orchestration
What it Does:
- Process requests
- Orchestrate AI calls
- Implement business rules
- Handle errors and retries
- Manage workflows
4. AI Services Layer
Section titled “4. AI Services Layer”Purpose: Intelligence and cognitive capabilities
Common Azure Services:
- Azure OpenAI Service: GPT models for generation
- Azure AI Services: Vision, speech, language understanding
- Azure Machine Learning: Custom model training and deployment
What it Does:
- Natural language understanding
- Text generation
- Embeddings creation
- Image analysis
- Speech recognition/synthesis
5. Data & Search Layer
Section titled “5. Data & Search Layer”Purpose: Store and retrieve information
Common Azure Services:
- Azure AI Search: Vector and hybrid search
- Azure Cosmos DB: NoSQL database for documents
- Azure SQL Database: Relational data
- Azure Storage: Blobs, files, tables
- Azure Cache for Redis: Fast data caching
What it Does:
- Store product catalogs
- Index content for search
- Cache frequent queries
- Manage user sessions
- Store conversation history
6. Monitoring & Observability
Section titled “6. Monitoring & Observability”Purpose: Track performance and issues
Common Azure Services:
- Azure Monitor: Comprehensive monitoring
- Application Insights: Application performance
- Log Analytics: Centralized logging
- Azure Managed Grafana: Visualization dashboards
What it Does:
- Track API calls
- Monitor costs
- Alert on errors
- Visualize metrics
- Trace requests
The RAG Architecture Pattern
Section titled “The RAG Architecture Pattern”Retrieval Augmented Generation (RAG) is the most common pattern for enterprise AI applications. Let’s break it down:
RAG Components
Section titled “RAG Components”User Query ↓1. Query Processing ↓2. Embedding Generation (Azure OpenAI) ↓3. Vector Search (Azure AI Search) ↓4. Context Retrieval (Top-K relevant documents) ↓5. Prompt Construction (Query + Context) ↓6. LLM Generation (Azure OpenAI GPT) ↓Response to UserWhy RAG?
Section titled “Why RAG?”Without RAG: LLMs only know what they were trained on (limited, potentially outdated)
With RAG: LLMs can access your specific data (current, relevant, accurate)
RAG Benefits
Section titled “RAG Benefits”- Accuracy: Responses grounded in your data
- Freshness: Use up-to-date information
- Transparency: Show source documents
- Control: Filter what data the model can access
- Cost: More efficient than fine-tuning
Retail AI Architecture Example
Section titled “Retail AI Architecture Example”Let’s apply this to our retail assistant:
Architecture Diagram
Section titled “Architecture Diagram” [Users] ↓ [Static Web App] Frontend ↓ [API Management Gateway] Auth + Rate Limiting ↓ [Azure Container Apps] Backend Services ↓ ┌──────────────┴──────────────┐ ↓ ↓[Azure OpenAI Service] [Azure AI Search] - Embeddings Model - Product Catalog Index - GPT-4 Completion - Policy Documents Index ↓ ↓ └──────────────┬──────────────┘ ↓ [Azure Cosmos DB] Conversation History ↓ [Application Insights] MonitoringRequest Flow
Section titled “Request Flow”-
User asks: “Show me waterproof hiking boots under $150”
-
Frontend sends request to API Gateway
-
API Gateway authenticates user, routes to backend
-
Backend creates embedding of query using Azure OpenAI
-
AI Search finds relevant products using vector search
-
Backend constructs prompt with query + search results
-
Azure OpenAI generates conversational response with product recommendations
-
Backend stores conversation in Cosmos DB
-
Frontend displays response to user
-
Application Insights tracks the entire request flow
Identifying Resources
Section titled “Identifying Resources”When reviewing an architecture diagram, ask:
For Each Service
Section titled “For Each Service”- What category? (Compute, Storage, AI, Networking, etc.)
- What purpose? (What problem does it solve?)
- Why this service? (Why not alternatives?)
- How does it connect? (What calls it? What does it call?)
For The Whole System
Section titled “For The Whole System”- What’s the entry point? (Where do requests start?)
- What’s the critical path? (Main flow for key scenarios)
- Where’s the data? (Storage and retrieval patterns)
- What could fail? (Single points of failure)
- How does it scale? (Bottlenecks and scaling strategies)
Architecture Best Practices
Section titled “Architecture Best Practices”Security
Section titled “Security”- API authentication and authorization
- Network isolation (VNets, Private Endpoints)
- Secrets management (Key Vault)
- Content filtering on AI outputs
Reliability
Section titled “Reliability”- Retry policies with exponential backoff
- Circuit breakers for failing services
- Health checks and monitoring
- Multi-region deployment (if needed)
Performance
Section titled “Performance”- Caching at multiple layers
- Async processing where possible
- Connection pooling
- CDN for static assets
Cost Optimization
Section titled “Cost Optimization”- Right-size resource SKUs
- Use consumption-based pricing
- Implement caching to reduce AI calls
- Monitor and alert on spending
Ask Copilot
Section titled “Ask Copilot”Explore architecture concepts:
- “What are the trade-offs between using Azure Functions versus Azure Container Apps for hosting AI application backend services?”
- “How do you implement caching effectively in a RAG architecture to reduce costs and improve response times?”
- “What are the key security considerations when exposing Azure OpenAI Service through a public-facing API?”
Related Resources
Section titled “Related Resources”- Baseline OpenAI End-to-End Chat Architecture
- Azure OpenAI Landing Zone
- Vector Search in Azure AI Search
- Prompt Engineering Guide
Next: Day 5 - Manual Provisioning
Tomorrow we’ll get hands-on with manual resource provisioning to understand what happens under the hood.