Google Cloud Platform (GCP) is one of the three largest public clouds, and it is especially strong in data analytics, Kubernetes and AI. These Google Cloud interview questions cover the core services and concepts that cloud, DevOps and data engineering interviews focus on.
Fundamentals
1. How is GCP organised?
Resources sit in a hierarchy: organization > folders > projects > resources. A project is the basic unit for billing, APIs and permissions. Policies set at a higher level are inherited below.
2. Explain regions and zones.
A region is a geographic location, such as asia-south1 (Mumbai) or asia-south2 (Delhi). Each region has several zones. For high availability, spread workloads across zones, and for disaster recovery, across regions.
3. How does IAM work in Google Cloud?
IAM grants roles to principals, such as users, groups and service accounts, on a resource. Roles can be basic (Owner, Editor, Viewer), predefined or custom. Best practice is to avoid basic roles and grant the narrowest predefined role.
4. What is a service account?
A service account is an identity for applications and VMs, not people. Applications use it to call Google APIs. Prefer attached service accounts or workload identity federation over downloaded keys, because leaked keys are a common cause of breaches.
Compute
5. Compare the main compute options.
| Service | What it is | Use it for |
|---|---|---|
| Compute Engine | Virtual machines | Full control of the OS |
| Google Kubernetes Engine (GKE) | Managed Kubernetes | Containerised microservices |
| Cloud Run | Serverless containers | Stateless web apps and APIs |
| Cloud Run functions | Event-driven functions | Small pieces of code triggered by events |
| App Engine | Platform as a service | Simple web apps |
6. What are Spot VMs?
Spot VMs use spare capacity at a large discount. However, Google can stop them at any time, so they suit batch and fault-tolerant jobs.
7. GKE Standard vs GKE Autopilot?
In Standard mode, you manage the nodes. In Autopilot, Google manages nodes and you pay for the pods’ resources, which reduces operational work.
Storage and data
8. What is Cloud Storage?
Cloud Storage is object storage organised in buckets. Its storage classes are Standard, Nearline, Coldline and Archive, from frequently accessed data to long-term archives with lower storage cost but higher retrieval cost.
9. Which database would you choose?
- Cloud SQL: managed MySQL, PostgreSQL and SQL Server.
- AlloyDB: high-performance PostgreSQL-compatible database.
- Spanner: globally distributed relational database with strong consistency.
- Firestore: serverless NoSQL document database.
- Bigtable: wide-column NoSQL for very large, low-latency workloads.
10. What is BigQuery?
BigQuery is a serverless data warehouse. You run SQL over very large datasets without managing servers. Billing is based on data scanned or on reserved capacity. Partitioning and clustering tables reduce cost and speed up queries.
11. What is Pub/Sub?
Pub/Sub is a messaging service. Publishers send messages to topics, and subscribers receive them. As a result, systems stay loosely coupled.
Networking
12. What is special about a GCP VPC?
A VPC network is global, while its subnets are regional. Therefore, VMs in different regions can communicate over Google’s private network without extra configuration.
13. Describe Cloud Load Balancing.
Google offers global and regional load balancers for HTTP(S), TCP and UDP traffic. The global external Application Load Balancer uses a single anycast IP address worldwide.
14. What is Cloud NAT?
Cloud NAT lets VMs without public IP addresses reach the internet for updates, while blocking unsolicited inbound connections.
Security and operations
15. How do you secure a GCP project?
- Use least-privilege IAM and avoid basic roles.
- Enforce organization policies, such as blocking service account key creation.
- Enable Cloud Audit Logs and review them.
- Use VPC Service Controls for sensitive data.
- Encrypt data, optionally with customer-managed keys in Cloud KMS.
- Monitor findings in Security Command Center.
16. What is Cloud Monitoring and Cloud Logging?
They form Google Cloud Observability: metrics, dashboards, alerts and centralised logs for GCP and other environments.
17. How do you control costs?
Set budgets and alerts, use committed use discounts for steady workloads, rightsize VMs, and use Spot VMs or autoscaling where possible.
For a broader view, see our cloud computing interview questions and AWS interview questions.
Keep preparing
Practise each answer out loud, and run the commands in a lab rather than memorising them. Interviewers often ask follow-up questions, so make sure you understand why each answer is true.
Sources
Preparing for an interview? Browse more questions in our interview preparation hub. For businesses, we also offer security services such as VAPT, server hardening and ISO 27001 readiness.
