Cloud-Agnostic Microservices Architecture for Personal Banking

pls architect and design same use case with hyperscaler so that it can be deployed to any cloud like aws,aure or gcp

🌐 Cloud-Agnostic Microservices Architecture for Personal Banking

🧱 Core Design Principles

• Use containers (Docker) and orchestration via Kubernetes (EKS, AKS, GKE).

• Service Mesh (Istio) for traffic management, observability, and policy enforcement.

• Abstracted cloud services via interfaces or platform services (e.g., Kafka instead of native queues).

• Infrastructure as Code using Terraform or Pulumi.

• CI/CD via Jenkins/GitHub Actions/Azure DevOps pipelines.

• Secret management via Vault or SOPS.

• Observability using Prometheus + Grafana, ELK Stack.

🏗️ High-Level Architecture Components

🔐 Security

• Identity Provider: Keycloak / Auth0 (can integrate with Azure AD, AWS Cognito, or GCP IAM)

• JWT-based authentication

• SSO & Role-Based Access Control (RBAC)

• SSL termination at Ingress gateway

📦 Microservices (Spring Boot based, packaged as Docker containers)

1. Customer Service

2. Account Service

3. Transaction Service

4. UPI Payment Service

5. Loan Processing Service

6. Fraud Detection Service

7. Notification Service

8. Audit & Compliance Service

9. API Gateway (Kong / Apigee / Istio Ingress)

📨 Event-Driven Architecture

• Message Broker: Apache Kafka (can be self-hosted or use Confluent Cloud)

• Async flows: Loan processing, fraud analysis, notification, audit logging

💾 Persistence Layer

• PostgreSQL / MySQL (cloud-neutral RDBMS options)

• MongoDB (for document-based use cases)

• Redis (caching layer)

🔍 Observability

• Logs: Fluentd + Elasticsearch

• Metrics: Prometheus + Grafana

• Tracing: Jaeger

☁️ Multi-Cloud Deployment Strategy

Layer	Services/Tools	Purpose
Compute	Kubernetes (EKS/AKS/GKE/on-prem)	Container orchestration
Networking	Istio + Ingress + DNS + Load Balancer	Traffic routing, mTLS, resilience
Storage	Cloud-native persistent volumes (PVCs)	Data persistence
Messaging	Kafka	Asynchronous communication
API Management	Kong / Apigee / Tyk	Central API gateway
Secrets Management	HashiCorp Vault	Secure config and secrets
Monitoring	Prometheus + Grafana + ELK Stack	Observability
CI/CD	Jenkins / GitHub Actions / Azure DevOps	Continuous delivery & infrastructure

🔁 Integration Strategy

• Use OpenAPI/Swagger for service contracts

• gRPC for internal service communication (optional)

• REST APIs for external consumers

• Kafka Topics for decoupled services

• Config server (Spring Cloud Config / HashiCorp Consul)

🛡️ Enterprise Risk Categories & Mitigation (Examples)

Category	Risk	Mitigation
Technology	Vendor lock-in	Use open-source, cloud-neutral components
Security	Cross-region access breach	Use service mesh with mTLS, centralized auth
Compliance	Multi-cloud data residency	Encrypt data, geo-based storage compliance
Operations	Complex multi-cloud deployments	Use GitOps, IaC, managed Kubernetes clusters