Top 20 GCP Cloud Interview Questions and Detailed Answers

1. Explain Google Cloud Platform (GCP) in your own words. What are its key differentiators compared to AWS and Azure?

GCP is Google’s suite of cloud computing services, built on their global infrastructure. Key differentiators include its high-performance global network, strengths in data analytics and machine learning (BigQuery, Vertex AI), leadership in containerization with Kubernetes (GKE), commitment to open source, and often a competitive pricing model with sustained use discounts.

2. Describe the fundamental resource hierarchy in GCP (Organization, Folders, Projects). Why is this structure important?

The hierarchy provides a logical organization: Organization (root, company-wide control), Folders (logical groupings), Projects (resource containers). Importance: centralized management, cost control, granular access control (IAM), logical organization, and policy inheritance.

3. What are Projects in GCP? How are they used for billing and resource isolation?

Projects are core organizational units for resources. Billing is set up at the Project level, aggregating usage costs. Projects provide logical isolation; resources in different Projects cannot directly interact without explicit configuration (e.g., VPC peering). IAM policies are also Project-scoped by default.

4. Explain the concept of Zones and Regions in GCP. How do you choose the appropriate ones for your applications?

Regions are global geographic areas, while Zones are isolated locations within a Region. Choose based on: latency, high availability, disaster recovery, compliance, cost, service availability.

5. What are some key Identity and Access Management (IAM) concepts in GCP? How do you grant least privilege?

Key concepts: Principals, Roles, Policies. Least privilege: grant minimum necessary permissions via specific/custom roles at the lowest scope.

II. Compute Services

6. Explain the purpose and benefits of Google Compute Engine (GCE). What are some different machine types available?

GCE is GCP’s IaaS for scalable VMs. Benefits: flexibility, performance, cost-effectiveness, global availability. Machine types: general-purpose, compute-optimized, memory-optimized, accelerated-computing.

7. What are Managed Instance Groups (MIGs) in GCE? How do they contribute to scalability and high availability?

MIGs manage groups of identical VMs. Enable scalability via autoscaling/manual resize. Achieve HA via auto-repair, regional deployment, load balancer integration.

8. What is Google Kubernetes Engine (GKE)? What are its benefits, and when would you use it?

GKE is a managed Kubernetes service. Benefits: managed control plane, autoscaling, GCP integration, security, simplified management. Use for microservices, scalable apps, containerized workloads.

9. What is Google Cloud Functions? What are its use cases and limitations?

Cloud Functions is a serverless, event-driven compute service. Use cases: event processing, API backends. Limitations: execution time, memory, stateless.

10. Describe Google Cloud Run. How does it differ from Cloud Functions and Compute Engine?

Cloud Run is a serverless platform for running stateless containers. Differences: container-based, scales to zero, longer execution than Functions, less VM control than Compute Engine.

11. Explain the purpose and benefits of Google BigQuery. What are some use cases relevant to retail/supply chain?

BigQuery is a serverless data warehouse for fast SQL on large datasets. Benefits: serverless, scalable, fast, cost-effective. Retail/Supply Chain Use Cases: analyzing sales, inventory, customers, logistics, forecasting.

12. What is Google Cloud Dataflow? What programming model does it use, and what types of data processing is it suitable for in a retail/supply chain context?

Dataflow is a serverless data processing service (Apache Beam). Suitable for ETL, data enrichment, stream processing (e.g., inventory, sales).

13. What is Google Cloud Pub/Sub? How can it be used in a retail/supply chain environment?

Pub/Sub is a real-time messaging service for decoupled communication. Retail/Supply Chain Use Cases: inventory updates, order notifications, supply chain event workflows.

14. Describe the different types of Cloud Storage offered by GCP (Cloud Storage, Nearline, Coldline, Archive). When would you choose each, potentially in a retail context?

Standard (active product data), Nearline (monthly reports), Coldline (yearly data), Archive (compliance). Choose based on access frequency vs. cost.

15. What is VPC? How do you create a secure network for retail applications in GCP?

VPC is a global private network. Secure retail networks involve VPCs, subnet segmentation, restrictive firewall rules, network tags/service accounts, VPC Service Controls.

16. Explain the concept of Service Accounts in GCP. How are they used for authentication in retail applications?

Service Accounts are non-human accounts for applications. Retail apps use them for secure authentication without user credentials, following least privilege.

17. What are some best practices for cost optimization in GCP, particularly relevant for a retail business with fluctuating demand?

Rightsizing, sustained use discounts, preemptible VMs (batch jobs), auto-scaling (Compute Engine, GKE), storage tiering, monitoring spending.

18. How would you monitor the health and performance of a retail application running on GKE in GCP?

Use Cloud Monitoring (metrics, dashboards, alerts), Cloud Logging (logs), and Cloud Trace (latency analysis).

19. What are some common troubleshooting steps you would take for a slow-performing retail website hosted on Compute Engine in GCP?

Check Cloud Monitoring (CPU, memory, network), Cloud Logging (errors), SSH into instance (`top`, `htop`), analyze web server logs, profile application, check database performance.

20. How would you approach designing a highly available and scalable infrastructure for a retail e-commerce platform on GCP?

Design would include: regional MIGs for web servers with auto-scaling and load balancing, multi-zone GKE for containerized applications, Cloud SQL with read replicas or Spanner for the database, Cloud Storage for product images and static content (with CDN), Cloud Pub/Sub for asynchronous tasks (order processing), and robust monitoring/alerting.

Summary of Top 20 GCP Cloud Interview Questions

These questions cover a broad range of essential GCP concepts and services, focusing on core infrastructure (Compute Engine, GKE), data and analytics (BigQuery, Dataflow, Pub/Sub), storage and networking, security and cost management, and monitoring/operations. Several questions also emphasize the application of these services within a retail/supply chain context, highlighting the practical considerations for real-world scenarios. Demonstrating a strong understanding of these areas, along with the ability to articulate design principles for scalability and high availability, will be crucial for a successful GCP cloud interview.