10 ‐ Popular scenarios commonly asked in Cloud Architect interviews - SanjeevOCI/Study GitHub Wiki

Popular Scenarios Commonly Asked in Cloud Architect Interviews (OCI & Azure)

1. Multi-Cloud or Hybrid Cloud Architecture

Scenario:
Your organization wants to deploy a hybrid cloud solution where sensitive workloads remain on-premises, and scalable workloads are deployed in the cloud.

  • OCI:

    • Use Dynamic Routing Gateway (DRG) to connect on-premises to OCI via VPN or FastConnect.
    • Use Service Gateway for private access to OCI services like Object Storage.
    • Implement VCN Peering for inter-VCN communication.

  • Azure:

    • Use VPN Gateway or ExpressRoute for hybrid connectivity.
    • Use Azure Virtual WAN for centralized hybrid network management.
    • Implement Azure Arc for managing on-premises and multi-cloud resources.

2. Disaster Recovery (DR)

Scenario:
Design a disaster recovery solution for a mission-critical application with an RTO of 15 minutes and an RPO of 5 minutes.

  • OCI:

    • Use Object Storage Replication for file backups across regions.
    • Use Data Guard for database replication between primary and DR regions.
    • Implement Traffic Management Steering Policies for DNS-based failover.

  • Azure:

    • Use Azure Site Recovery (ASR) for VM replication and failover.
    • Enable Geo-Replication for Azure Blob Storage.
    • Use Azure Traffic Manager for DNS-based failover across regions.

3. High Availability and Scalability

Scenario:
You need to design a highly available and scalable architecture for a web application with unpredictable traffic spikes.

  • OCI:

    • Use Load Balancer for traffic distribution across multiple compute instances.
    • Deploy compute instances in multiple Availability Domains (ADs) for high availability.
    • Use Instance Pools with auto-scaling to handle traffic spikes.

  • Azure:

    • Use Azure Load Balancer or Azure Front Door for traffic distribution.
    • Deploy VMs in multiple Availability Zones for high availability.
    • Use Virtual Machine Scale Sets (VMSS) for auto-scaling.

4. Secure Connectivity

Scenario:
You need to securely connect multiple VNets or VCNs across regions and clouds.

  • OCI:

    • Use Local Peering Gateway (LPG) for intra-region VCN peering.
    • Use Remote Peering Gateway (RPG) for inter-region VCN peering.
    • Use DRG for connecting OCI to other clouds or on-premises.

  • Azure:

    • Use VNet Peering for intra-region and inter-region VNet communication.
    • Use Azure Virtual WAN for centralized connectivity across regions and clouds.
    • Use VPN Gateway or ExpressRoute for hybrid connectivity.

5. Cost Optimization

Scenario:
Your organization is experiencing high cloud costs. How would you optimize the cloud infrastructure?

  • OCI:

    • Use Cost Analysis in the OCI Console to identify underutilized resources.
    • Use Always Free Tier for eligible workloads.
    • Implement Auto Scaling to shut down idle compute instances.

  • Azure:

    • Use Azure Cost Management to analyze and optimize costs.
    • Use Azure Reserved Instances for predictable workloads.
    • Implement Auto-Scaling to shut down idle VMs.

6. CI/CD Pipeline

Scenario:
Design a CI/CD pipeline for a microservices-based application hosted in the cloud.

  • OCI:

    • Use OCI DevOps for automated builds, tests, and deployments.
    • Integrate with GitHub or GitLab for source control.
    • Use Container Registry and OKE (Oracle Kubernetes Engine) for containerized deployments.

  • Azure:

    • Use Azure DevOps or GitHub Actions for CI/CD.
    • Deploy containerized workloads to Azure Kubernetes Service (AKS).
    • Use Azure Container Registry (ACR) for managing container images.

7. Data Migration

Scenario:
Your organization wants to migrate a large on-premises database to the cloud with minimal downtime.

  • OCI:

    • Use OCI Database Migration Service for Oracle and non-Oracle databases.
    • Use GoldenGate for real-time replication and minimal downtime.
    • Validate data integrity post-migration.

  • Azure:

    • Use Azure Database Migration Service (DMS) for SQL and NoSQL databases.
    • Enable Change Data Capture (CDC) for near-zero downtime.
    • Validate data integrity post-migration.

8. Security and Compliance

Scenario:
Design a secure architecture for a healthcare application that must comply with HIPAA regulations.

  • OCI:

    • Use IAM Policies and Dynamic Groups for least privilege access.
    • Encrypt data at rest using OCI Vault.
    • Use WAF (Web Application Firewall) and DDoS Protection for application security.

  • Azure:

    • Use Azure Active Directory (AAD) for identity and access management.
    • Encrypt data at rest using Azure Key Vault.
    • Use Azure WAF and DDoS Protection for application security.

9. Serverless Architecture

Scenario:
Your organization wants to build a cost-effective serverless architecture for a REST API.

  • OCI:

    • Use OCI Functions for serverless compute.
    • Use API Gateway to expose the REST API.
    • Store data in Autonomous JSON Database or Object Storage.

  • Azure:

    • Use Azure Functions for serverless compute.
    • Use Azure API Management to expose the REST API.
    • Store data in Cosmos DB or Azure Blob Storage.

10. Multi-Region Deployment

Scenario:
You need to deploy an application across multiple regions to reduce latency for global users.

  • OCI:

    • Deploy resources in multiple OCI regions.
    • Use Traffic Management Steering Policies for DNS-based routing.
    • Replicate databases using Data Guard or GoldenGate.

  • Azure:

    • Deploy resources in multiple Azure regions.
    • Use Azure Traffic Manager for DNS-based routing.
    • Enable Geo-Replication for Azure Blob Storage and databases.

11. Logging and Monitoring

Scenario:
How would you design a logging and monitoring solution for a cloud-native application?

  • OCI:

    • Use OCI Monitoring for metrics and alarms.
    • Use OCI Logging for centralized log management.
    • Integrate with Service Connector Hub for exporting logs to external tools.

  • Azure:

    • Use Azure Monitor for metrics and alerts.
    • Use Azure Log Analytics for centralized log management.
    • Integrate with Azure Sentinel for advanced security analytics.

12. Autoscaling

Scenario:
Your application experiences unpredictable traffic spikes. How would you ensure it scales automatically?

  • OCI:

    • Use Instance Pools with auto-scaling policies.
    • Deploy a Load Balancer to distribute traffic across instances.
    • Use OKE (Oracle Kubernetes Engine) for containerized workloads.

  • Azure:

    • Use Virtual Machine Scale Sets (VMSS) for auto-scaling.
    • Deploy an Azure Load Balancer to distribute traffic.
    • Use AKS (Azure Kubernetes Service) for containerized workloads.

13. Networking

Scenario:
You need to connect two VNets/VCNs in different regions securely.

  • OCI:

    • Use Remote Peering Gateway (RPG) for inter-region VCN peering.
    • Ensure proper route table and security list configurations.

  • Azure:

    • Use VNet Peering for inter-region connectivity.
    • Configure User-Defined Routes (UDRs) for traffic routing.

14. Cost Management

Scenario:
Your cloud costs are increasing due to unused resources. How would you optimize costs?

  • OCI:

    • Identify underutilized resources using Cost Analysis.
    • Use Always Free Tier for eligible workloads.
    • Implement Auto Scaling to shut down idle resources.

  • Azure:

    • Use Azure Cost Management to analyze and optimize costs.
    • Use Azure Reserved Instances for predictable workloads.
    • Implement Auto-Scaling to shut down idle VMs.

These scenarios are designed to test your technical expertise, problem-solving skills, and architectural decision-making for both OCI and Azure platforms.

Here are popular scenarios commonly asked in Cloud Architect interviews across various cloud platforms (AWS, Azure, GCP, OCI):

1. Multi-Cloud or Hybrid Cloud Architecture

Scenario:
Your organization wants to deploy a hybrid cloud solution where sensitive workloads remain on-premises, and scalable workloads are deployed in the cloud. How would you design this architecture?

Key Points to Address:

  • Use VPN Gateway or ExpressRoute (Azure) / Direct Connect (AWS) for secure connectivity.
  • Implement Identity Federation for unified access control.
  • Use Cloud Storage Gateways for seamless data transfer.
  • Ensure data encryption and compliance for sensitive workloads.

2. Disaster Recovery (DR)

Scenario:
Design a disaster recovery solution for a mission-critical application with an RTO of 15 minutes and an RPO of 5 minutes.

Key Points to Address:

  • Use Active-Passive DR with Data Replication (e.g., AWS RDS Multi-Region, Azure Geo-Replication).
  • Automate failover using DNS-based routing (e.g., Route 53, Azure Traffic Manager).
  • Use Object Storage Replication for file backups.
  • Implement Infrastructure as Code (IaC) for quick recovery.

3. High Availability and Scalability

Scenario:
You need to design a highly available and scalable architecture for a web application with unpredictable traffic spikes.

Key Points to Address:

  • Use Auto Scaling Groups (AWS) / VM Scale Sets (Azure) / Managed Instance Groups (GCP) for compute scaling.
  • Deploy Load Balancers for traffic distribution.
  • Use CDNs (e.g., CloudFront, Azure CDN) for caching static content.
  • Implement multi-AZ or multi-region deployments for high availability.

4. Secure Connectivity

Scenario:
You need to securely connect multiple VNets or VPCs across regions and clouds.

Key Points to Address:

  • Use Hub-and-Spoke Architecture with Transit Gateway (AWS) or Azure Virtual WAN.
  • Implement VPC Peering or Interconnects for intra-cloud communication.
  • Use VPN or ExpressRoute/Direct Connect for hybrid connectivity.
  • Ensure encryption in transit and firewall rules for traffic control.

5. Cost Optimization

Scenario:
Your organization is experiencing high cloud costs. How would you optimize the cloud infrastructure?

Key Points to Address:

  • Identify underutilized resources using Cost Analysis Tools (e.g., AWS Cost Explorer, Azure Cost Management).
  • Use Reserved Instances or Savings Plans for predictable workloads.
  • Implement Auto Scaling to shut down idle resources.
  • Use Spot Instances for non-critical workloads.

6. CI/CD Pipeline

Scenario:
Design a CI/CD pipeline for a microservices-based application hosted in the cloud.

Key Points to Address:

  • Use GitHub Actions, Jenkins, or Azure DevOps for CI/CD.
  • Automate builds, tests, and deployments using Docker and Kubernetes.
  • Use Infrastructure as Code (IaC) tools like Terraform or CloudFormation.
  • Implement Blue-Green Deployments or Canary Releases for zero-downtime updates.

7. Data Migration

Scenario:
Your organization wants to migrate a large on-premises database to the cloud with minimal downtime.

Key Points to Address:

  • Use Database Migration Services (e.g., AWS DMS, Azure DMS).
  • Implement Change Data Capture (CDC) for real-time replication.
  • Use GoldenGate or native tools for near-zero downtime.
  • Validate data integrity post-migration.

8. Security and Compliance

Scenario:
Design a secure architecture for a healthcare application that must comply with HIPAA regulations.

Key Points to Address:

  • Use IAM Policies and Role-Based Access Control (RBAC) for least privilege.
  • Encrypt data at rest using KMS (AWS) or Azure Key Vault.
  • Use WAF and DDoS Protection for application security.
  • Implement audit logging and monitoring for compliance.

9. Serverless Architecture

Scenario:
Your organization wants to build a cost-effective serverless architecture for a REST API.

Key Points to Address:

  • Use AWS Lambda, Azure Functions, or GCP Cloud Functions for compute.
  • Use API Gateway for exposing the API.
  • Store data in DynamoDB (AWS) or Cosmos DB (Azure).
  • Implement CloudWatch or Azure Monitor for monitoring.

10. Multi-Region Deployment

Scenario:
You need to deploy an application across multiple regions to reduce latency for global users.

Key Points to Address:

  • Use Global Load Balancers (e.g., AWS Global Accelerator, Azure Front Door).
  • Deploy resources in multiple regions with replicated databases (e.g., Aurora Global DB, Cosmos DB).
  • Use CDNs for caching static content.
  • Implement DNS-based routing for directing users to the nearest region.

11. Logging and Monitoring

Scenario:
How would you design a logging and monitoring solution for a cloud-native application?

Key Points to Address:

  • Use CloudWatch (AWS), Azure Monitor, or GCP Operations Suite for metrics and logs.
  • Implement centralized logging using tools like ELK Stack or Azure Log Analytics.
  • Set up alerts for critical thresholds.
  • Use distributed tracing for microservices (e.g., AWS X-Ray, Azure Application Insights).

12. File Storage and Backup

Scenario:
Your application needs to store large files and ensure regular backups.

Key Points to Address:

  • Use Object Storage (e.g., S3, Azure Blob Storage, GCP Cloud Storage).
  • Implement Lifecycle Policies to move infrequently accessed files to cheaper storage tiers.
  • Use Cross-Region Replication for disaster recovery.
  • Automate backups using Cloud Backup Services.

13. Autoscaling

Scenario:
Your application experiences unpredictable traffic spikes. How would you ensure it scales automatically?

Key Points to Address:

  • Use Auto Scaling Groups (AWS), VM Scale Sets (Azure), or Managed Instance Groups (GCP).
  • Configure scaling policies based on metrics like CPU utilization or request count.
  • Use Load Balancers to distribute traffic evenly.
  • Implement serverless solutions for highly dynamic workloads.

14. Networking

Scenario:
You need to connect two VNets/VPCs in different regions securely.

Key Points to Address:

  • Use VPC Peering or Transit Gateway (AWS).
  • For Azure, use VNet Peering or Azure Virtual WAN.
  • Ensure firewall rules and route tables are configured correctly.
  • Use encryption in transit for secure communication.

15. Cost Management

Scenario:
Your cloud costs are increasing due to unused resources. How would you optimize costs?

Key Points to Address:

  • Identify unused resources using Cost Analysis Tools (e.g., AWS Cost Explorer, Azure Cost Management).
  • Use Reserved Instances or Savings Plans for predictable workloads.
  • Implement auto-scaling to shut down idle resources.
  • Use Spot Instances for non-critical workloads.

These scenarios are designed to test your technical expertise, problem-solving skills, and architectural decision-making as a Cloud Architect.