Architecture & Design – Spring Boot Microservices on Azure Cloud

🏗️ Architecture & Design – Spring Boot Microservices on Azure Cloud

🔹 1. High-Level Architecture Components

• Spring Boot Microservices: Built using REST, JPA, Spring Security

• API Gateway: Azure API Management (APIM)

• Service Discovery: Istio or Azure App Configuration

• Communication: REST + Kafka for async/event-driven

• Security: Azure AD (OAuth2), JWT, API Key, Role-based access

• Data: Azure SQL, Cosmos DB, Azure Blob Storage

• CI/CD: Azure DevOps (build, test, deploy pipelines)

• Observability: Azure Monitor, Application Insights

• Containers: Dockerized apps, Azure Container Registry (ACR)

• Orchestration: Azure Kubernetes Service (AKS)

• Secrets: Azure Key Vault

• Load Balancer: Azure Load Balancer with DNS + SSL

• Network: VPC, Subnets, NSGs, Azure Firewall

  
  

🔹 2. Design Principles

• Domain-Driven Design (DDD) for Bounded Contexts

• API First: Swagger/OpenAPI + API Gateway

• Circuit Breakers & Retry: Resilience4j or Istio policies

• Asynchronous Messaging: Kafka for decoupled communication

• Observability: Logs, Traces, Metrics with Azure Monitor stack

• Security by Design: RBAC, OAuth2, SSO, secret management

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🔹 3. Azure Cloud Integration

Component	Azure Service
Container Hosting	AKS
Networking	VNet, Subnets, NSG
DNS & SSL	Traffic Manager + Load Balancer
Auth	Azure AD + SSO
API Management	Azure API Management
Observability	Azure Monitor, Log Analytics
CI/CD	Azure DevOps
Registry	ACR
Event Bus	Azure Event Hub / Kafka
Database	Azure SQL / Cosmos DB
Secrets	Azure Key Vault

🔹 4. Best Practices

• Use Helm for AKS deployments

• Separate dev/test/prod environments with isolated VNets

• Define SLAs and alerts in Azure Monitor

• Use AAD Pod Identity for secure access

• Set up Multi-AZ AKS clusters

• Enable mTLS and policies in Istio for service mesh

• Store config in Azure App Configuration or Consul

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🔹 5. Interview Focus Areas

• Design microservice per domain

• Resilience patterns with Istio or Resilience4j

• Token validation via Spring Security + Azure AD

• Kafka topic design and producer/consumer error handling

• Blue/green or canary deployment strategy on AKS

• Secure communication via mTLS or API Gateway

• Role of service mesh, API gateway, and CI/CD flows