Cloud skills are now expected in most IT roles, from system administration to development and security. These cloud computing interview questions focus on concepts that apply to every provider, including AWS, Azure and Google Cloud, so you can answer confidently whichever platform the employer uses.
Fundamentals
1. What is cloud computing?
Cloud computing delivers computing resources, such as servers, storage, databases and software, over the internet on demand, with pay-as-you-go pricing.
2. Name the essential characteristics of cloud computing.
NIST lists five: on-demand self-service, broad network access, resource pooling, rapid elasticity and measured service.
3. Explain the service models.
| Model | You manage | Provider manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, virtualisation, networking | EC2, Azure VMs, Compute Engine |
| PaaS | Apps and data | Everything below the application | App Service, Elastic Beanstalk, Cloud Run |
| SaaS | Users and settings | The whole application | Microsoft 365, Salesforce, Gmail |
Serverless functions, such as AWS Lambda, are often called Function as a Service (FaaS).
4. Describe the deployment models.
- Public cloud: shared provider infrastructure.
- Private cloud: dedicated to one organization, on-premises or hosted.
- Hybrid cloud: public and private connected together.
- Multi-cloud: using more than one public provider.
5. What is the shared responsibility model?
The provider secures the underlying cloud. The customer secures what they deploy: data, identities, configurations and applications. The split changes with the service model.
Architecture
6. Scalability vs elasticity?
Scalability is the ability to handle more load by adding resources. Elasticity means adding and removing them automatically as demand changes.
7. Vertical vs horizontal scaling?
Vertical scaling makes one server bigger. Horizontal scaling adds more servers, which suits cloud-native applications and improves resilience.
8. How do you design for high availability?
Spread workloads across availability zones, use load balancers and auto scaling, replicate databases, store files in redundant object storage and remove single points of failure.
9. High availability vs disaster recovery?
High availability keeps services running through small failures, such as one server or zone. Disaster recovery restores services after a major event, such as losing a whole region, within agreed RTO and RPO targets.
10. What does cloud-native mean?
Cloud-native applications use microservices, containers, managed services, automation and continuous delivery, so they scale and recover easily.
11. What is serverless computing?
The provider runs and scales the servers, and you pay only for actual use. You focus on code and configuration. However, you accept limits such as execution time and cold starts.
Operations and cost
12. What is infrastructure as code?
Defining cloud resources in code, using tools like Terraform, OpenTofu, CloudFormation or Bicep, so environments are repeatable and version-controlled.
13. How do you control cloud costs?
Tag resources, set budgets and alerts, right-size instances, use reserved capacity or savings plans for steady workloads, use spot capacity where possible and delete unused resources. This practice is often called FinOps.
14. What is vendor lock-in, and how do you reduce it?
Lock-in happens when moving to another provider becomes costly. Containers, open standards, IaC and portable data formats reduce it, although some lock-in is often worth the benefits of managed services.
Security
15. What are the top cloud security risks?
Misconfigured storage, excessive permissions, leaked credentials, unpatched workloads and missing logging. Most breaches come from customer misconfiguration, not the provider.
16. How do you secure a cloud account?
Enforce MFA, use least-privilege roles, avoid long-lived keys, turn on audit logging, encrypt data, use posture management tools and review findings regularly.
For provider-specific questions, see our AWS, Azure and Google Cloud guides.
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.
