Cloud interview questions

Explain IaaS, PaaS, and SaaS with examples.

Easy · Cloud, Cloud Fundamentals, Fresher

What is the cloud shared responsibility model?

Easy · Cloud, Cloud Fundamentals, Fresher

What is the difference between a Region and an Availability Zone?

Easy · Cloud, Cloud Fundamentals, Fresher

Compare public cloud, private cloud, and hybrid cloud.

Easy · Cloud, Cloud Fundamentals, Fresher

What is elasticity vs scalability in the cloud?

Easy · Cloud, Cloud Fundamentals, Fresher

Explain CapEx vs OpEx in cloud economics.

Easy · Cloud, Cloud Fundamentals, Fresher

What are the six pillars of the AWS Well-Architected Framework?

Medium · Cloud, Cloud Fundamentals, Fresher

Explain RPO, RTO, and DR strategies (backup, pilot light, warm standby, active-active).

Medium · Cloud, Cloud Fundamentals, Senior

What causes cold starts in serverless, and how do you mitigate them?

Medium · Cloud, Cloud Fundamentals, Senior

How do you handle data residency and compliance in the cloud?

Hard · Cloud, Cloud Fundamentals, Architect

How do you choose EC2 instance families (general, compute, memory, storage optimised)?

Medium · Cloud, AWS, EC2

When do you choose EC2/containers over Lambda?

Medium · Cloud, AWS, EC2

Compare ECS vs EKS for running containers on AWS.

Medium · Cloud, AWS, ECS

ECS Fargate vs EC2 launch type — trade-offs?

Medium · Cloud, AWS, Fargate

How does EC2 Auto Scaling work? What metrics drive scaling policies?

Medium · Cloud, AWS, EC2

Explain On-Demand, Reserved, and Spot instances.

Medium · Cloud, AWS, EC2

How do you run Kubernetes workloads on AWS (EKS, node groups, add-ons)?

Hard · Cloud, AWS, EKS

Explain S3 storage classes and when to use each.

Easy · Cloud, AWS, S3

What are S3 durability, availability, and consistency guarantees?

Medium · Cloud, AWS, S3

Compare S3, EBS, and EFS.

Medium · Cloud, AWS, S3

What is Amazon RDS and which engines does it support?

Easy · Cloud, AWS, RDS

RDS Multi-AZ vs Read Replicas — differences?

Medium · Cloud, AWS, RDS

What makes Amazon Aurora different from standard RDS?

Medium · Cloud, AWS, Aurora

When do you choose DynamoDB over RDS?

Medium · Cloud, AWS, DynamoDB

How does DynamoDB partitioning work? What is a hot partition?

Hard · Cloud, AWS, DynamoDB

What is ElastiCache and Redis vs Memcached on AWS?

Medium · Cloud, AWS, ElastiCache

Explain VPC, subnets, route tables, and internet gateway.

Medium · Cloud, AWS, VPC

What is a NAT Gateway and why do private subnets need it?

Medium · Cloud, AWS, NAT

Security Groups vs Network ACLs?

Easy · Cloud, AWS, VPC

How do IAM users, roles, and policies work?

Medium · Cloud, AWS, IAM

What is IAM role assumption and cross-account access?

Hard · Cloud, AWS, IAM

Route 53 routing policies (simple, weighted, latency, failover, geolocation).

Medium · Cloud, AWS, Route53

Application Load Balancer vs Network Load Balancer?

Medium · Cloud, AWS, ALB

What are AWS WAF and Shield?

Medium · Cloud, AWS, WAF

How does AWS KMS encrypt data at rest and in transit?

Medium · Cloud, AWS, KMS

Compare SQS and SNS.

Easy · Cloud, AWS, SQS

SQS Standard vs FIFO queues?

Medium · Cloud, AWS, SQS

What is SQS visibility timeout and how do you tune it?

Medium · Cloud, AWS, SQS

Kinesis Data Streams vs SQS — when to use which?

Medium · Cloud, AWS, Kinesis

What is Amazon EventBridge?

Medium · Cloud, AWS, EventBridge

What does API Gateway provide for microservices?

Medium · Cloud, AWS, API Gateway

When do you use Step Functions?

Medium · Cloud, AWS, Step Functions

What is Amazon MSK (Managed Streaming for Kafka)?

Medium · Cloud, AWS, MSK

How does AWS Lambda work? Limits and pricing model?

Easy · Cloud, AWS, Lambda

Reserved vs provisioned concurrency in Lambda?

Hard · Cloud, AWS, Lambda

How do you handle Lambda failures and DLQs?

Medium · Cloud, AWS, Lambda

DynamoDB Streams + Lambda pattern?

Medium · Cloud, AWS, Serverless

Design a serverless REST API with API Gateway and Lambda.

Medium · Cloud, AWS, Serverless

CloudWatch metrics, alarms, and dashboards — best practices?

Medium · Cloud, AWS, CloudWatch

CloudWatch Logs vs CloudWatch Logs Insights?

Easy · Cloud, AWS, CloudWatch

What is AWS X-Ray and how does it help debug distributed systems?

Medium · Cloud, AWS, X-Ray

CloudTrail vs CloudWatch — when to use each?

Easy · Cloud, AWS, CloudTrail

Outline a CI/CD pipeline on AWS (CodeCommit/CodeBuild/CodeDeploy/CodePipeline).

Medium · Cloud, AWS, CI/CD

CloudFormation vs Terraform?

Medium · Cloud, AWS, IaC

Blue/green vs rolling deployments on AWS?

Medium · Cloud, AWS, CI/CD

Design a classic three-tier web application on AWS.

Medium · Cloud, AWS, Architecture

What are trade-offs of multi-region active-active on AWS?

Hard · Cloud, AWS, Multi-Region

Top AWS cost optimisation strategies?

Medium · Cloud, AWS, Cost

What are VPC endpoints and how do they reduce cost?

Medium · Cloud, AWS, VPC

How do you design for high availability and fault tolerance on AWS?

Medium · Cloud, AWS, HA

What is Google Compute Engine (GCE) and when do you choose it over managed services?

Easy · Cloud, GCP, Compute

How does Google Kubernetes Engine (GKE) work and what makes it different from self-managed Kubernetes?

Medium · Cloud, GCP, Compute

Compare GKE Autopilot vs GKE Standard mode.

Medium · Cloud, GCP, Compute

What is Cloud Run and how does it differ from GKE and App Engine?

Medium · Cloud, GCP, Compute

Explain App Engine Standard vs Flexible environments.

Medium · Cloud, GCP, Compute

How do Managed Instance Groups (MIGs) and autoscaling policies work on GCE?

Medium · Cloud, GCP, Compute

What are preemptible VMs and Spot VMs? How do you use them safely?

Medium · Cloud, GCP, Compute

How do you choose GCE machine families (E2, N2, C2, M, Tau)?

Medium · Cloud, GCP, Compute

What is GCE live migration and why does it matter for availability?

Easy · Cloud, GCP, Compute

Decision framework: when to use GCE vs GKE vs Cloud Run vs App Engine?

Hard · Cloud, GCP, Compute

Explain Cloud Storage classes and when to use each.

Easy · Cloud, GCP, Storage

How do GCS bucket versioning, uniform access, and IAM work together?

Medium · Cloud, GCP, Storage

What is Cloud SQL and how does high availability work?

Easy · Cloud, GCP, Database

How does AlloyDB differ from Cloud SQL?

Medium · Cloud, GCP, Database

When do you choose Firestore over Cloud SQL or Spanner?

Medium · Cloud, GCP, Database

What is Cloud Spanner and when is it the right choice?

Hard · Cloud, GCP, Database

How do you avoid hotspotting in Cloud Spanner?

Hard · Cloud, GCP, Database

What are Cloud Bigtable use cases and design principles?

Medium · Cloud, GCP, Database

Compare Memorystore for Redis vs Memcached.

Medium · Cloud, GCP, Database

How do you choose between Cloud SQL, AlloyDB, Spanner, Firestore, and Bigtable?

Hard · Cloud, GCP, Database

Explain VPC networks, subnets, and firewall rules in GCP.

Medium · Cloud, GCP, Networking

What is Shared VPC and when do you use it?

Hard · Cloud, GCP, Networking

What is Cloud NAT and how do you design it for high availability?

Medium · Cloud, GCP, Networking

How does GCP IAM work — roles, bindings, and policies?

Medium · Cloud, GCP, Security

What are service accounts and how do you secure them?

Medium · Cloud, GCP, Security

How does Workload Identity work on GKE?

Hard · Cloud, GCP, Security

What does Cloud DNS provide and how does routing work?

Easy · Cloud, GCP, Networking

Compare GCP load balancer types (HTTP(S), TCP/SSL proxy, Network, Internal).

Hard · Cloud, GCP, Networking

What is Cloud Armor and how do you protect applications with it?

Medium · Cloud, GCP, Security

How do Cloud KMS and Secret Manager work together?

Medium · Cloud, GCP, Security

Explain Pub/Sub topics, subscriptions, and message flow.

Easy · Cloud, GCP, Messaging

How do Pub/Sub dead-letter topics and retry policies work?

Medium · Cloud, GCP, Messaging

When do you use Cloud Tasks vs Pub/Sub?

Medium · Cloud, GCP, Messaging

What is Cloud Scheduler and common use cases?

Easy · Cloud, GCP, Integration

What is Eventarc and how does it route events?

Medium · Cloud, GCP, Integration

When do you use Workflows for orchestration?

Medium · Cloud, GCP, Integration

Compare Apigee vs Cloud Endpoints vs API Gateway.

Hard · Cloud, GCP, Integration

How do Pub/Sub and Dataflow integrate for stream processing?

Medium · Cloud, GCP, Messaging

How do Cloud Functions (2nd gen) work and what are key limits?

Easy · Cloud, GCP, Serverless

How does Cloud Run autoscaling, concurrency, and cold starts work?

Medium · Cloud, GCP, Serverless

Explain Cloud Logging architecture and best practices.

Medium · Cloud, GCP, Observability

How does Cloud Monitoring support SLOs and alerting?

Medium · Cloud, GCP, Observability

What is Cloud Trace and how do you instrument distributed systems?

Medium · Cloud, GCP, Observability

What are the types of Cloud Audit Logs?

Easy · Cloud, GCP, Observability

How do Logging, Monitoring, Trace, and Error Reporting work together?

Hard · Cloud, GCP, Observability

Outline a CI/CD pipeline with Cloud Build.

Medium · Cloud, GCP, DevOps

What is Artifact Registry and how do you secure container images?

Easy · Cloud, GCP, DevOps

Best practices for Terraform on GCP.

Medium · Cloud, GCP, DevOps

How do you design multi-region architectures on GCP?

Hard · Cloud, GCP, Architecture

Top GCP cost optimization and reliability strategies?

Medium · Cloud, GCP, Architecture

How do Spring Boot profiles work for cloud deployments?

Easy · Cloud, Java & Cloud, Spring Boot Config

Explain externalized configuration in Spring Boot for cloud-native apps.

Easy · Cloud, Java & Cloud, Spring Boot Config

How should Java services read environment variables in production?

Easy · Cloud, Java & Cloud, Spring Boot Config

When would you use Spring Cloud Config vs platform-native config (Parameter Store, Secret Manager)?

Medium · Cloud, Java & Cloud, Spring Boot Config

What are AWS SDK for Java v2 client builder best practices?

Medium · Cloud, Java & Cloud, AWS SDK v2

When should you use async AWS SDK v2 clients in Java?

Medium · Cloud, Java & Cloud, AWS SDK v2

How do you integrate Amazon S3 with a Spring Boot application?

Medium · Cloud, Java & Cloud, S3

How do you build a reliable SQS consumer in Spring Boot?

Medium · Cloud, Java & Cloud, SQS

Explain SNS fan-out patterns with Java producers.

Medium · Cloud, Java & Cloud, SNS

How do you access DynamoDB from Spring Boot?

Medium · Cloud, Java & Cloud, DynamoDB

How do you handle DynamoDB pagination and batch operations in Java?

Hard · Cloud, Java & Cloud, DynamoDB

How do you load secrets from AWS Secrets Manager in Spring Boot?

Medium · Cloud, Java & Cloud, Secrets Manager

How is AWS Systems Manager Parameter Store used with Java apps?

Medium · Cloud, Java & Cloud, Parameter Store

How do you use GCP Secret Manager with a Java/Spring service on Cloud Run or GKE?

Medium · Cloud, Java & Cloud, GCP Secret Manager

What does Spring Cloud AWS provide, and when should you adopt it?

Medium · Cloud, Java & Cloud, Spring Cloud AWS

How does Spring Cloud GCP simplify Google Cloud integration?

Medium · Cloud, Java & Cloud, Spring Cloud GCP

Compare @Scheduled, Amazon EventBridge, and Cloud Scheduler for Java workloads.

Medium · Cloud, Java & Cloud, Scheduling

When is Quartz still relevant in cloud-native Java applications?

Hard · Cloud, Java & Cloud, Scheduling

How do you prevent duplicate scheduled job execution across pods?

Medium · Cloud, Java & Cloud, Scheduling

What are the trade-offs of running Spring Boot on AWS Lambda?

Hard · Cloud, Java & Cloud, Lambda

How does Spring Cloud Function simplify serverless Java deployment?

Medium · Cloud, Java & Cloud, Lambda

How do you deploy a Spring Boot JAR to Google Cloud Run?

Medium · Cloud, Java & Cloud, Cloud Run

How do you configure Redis/ElastiCache caching in Spring Boot?

Medium · Cloud, Java & Cloud, Redis

What should Java developers know about ElastiCache vs Memorystore?

Easy · Cloud, Java & Cloud, Redis

How do you prevent cache stampede and thundering herd in cloud caches?

Hard · Cloud, Java & Cloud, Redis

How do you implement idempotency for cloud API handlers in Java?

Hard · Cloud, Java & Cloud, Idempotency

Explain the transactional outbox pattern for reliable event publishing.

Hard · Cloud, Java & Cloud, Outbox Pattern

How do you build an idempotent SQS message consumer?

Hard · Cloud, Java & Cloud, Message Consumers

How do you export Micrometer metrics to CloudWatch or GCP Monitoring?

Medium · Cloud, Java & Cloud, Observability

How do you add distributed tracing with OpenTelemetry in Spring Boot?

Medium · Cloud, Java & Cloud, Observability

What does production-grade structured logging look like in Java cloud services?

Medium · Cloud, Java & Cloud, Observability

How do you configure Spring Boot health checks for Kubernetes and ECS?

Medium · Cloud, Java & Cloud, Health Checks

How does graceful shutdown work for Spring Boot on Kubernetes?

Medium · Cloud, Java & Cloud, Graceful Shutdown

Outline a CI/CD pipeline deploying a Spring Boot app to AWS ECS.

Medium · Cloud, Java & Cloud, CI/CD

How do CI/CD flows differ for Java apps on EKS vs GKE?

Medium · Cloud, Java & Cloud, CI/CD

Explain DefaultCredentialsProvider and why static AWS keys are avoided.

Easy · Cloud, Java & Cloud, IAM & Credentials

How does workload identity work for Java apps on GKE and EKS?

Medium · Cloud, Java & Cloud, IAM & Credentials

What IAM practices matter for Java microservices calling AWS APIs?

Medium · Cloud, Java & Cloud, IAM & Credentials

How do you apply Resilience4j circuit breakers to cloud API calls?

Medium · Cloud, Java & Cloud, Resilience4j

When should you use Resilience4j retry vs SDK built-in retries?

Medium · Cloud, Java & Cloud, Resilience4j

Explain bulkhead and time limiter patterns for cloud dependencies.

Hard · Cloud, Java & Cloud, Resilience4j

How do Testcontainers improve integration testing for cloud-backed Java services?

Medium · Cloud, Java & Cloud, Testing

What are LocalStack limitations when testing AWS integrations?

Medium · Cloud, Java & Cloud, Testing

How do you test message contracts between Java services and cloud queues?

Hard · Cloud, Java & Cloud, Testing

What techniques help debug production issues in cloud-hosted Java services?

Medium · Cloud, Java & Cloud, Production Debugging

How do you tune database connection pools for cloud microservices?

Hard · Cloud, Java & Cloud, Connection Pooling

What patterns suit large batch processing in Java on cloud?

Medium · Cloud, Java & Cloud, Batch Processing

What cost-aware coding practices apply to Java cloud backends?

Medium · Cloud, Java & Cloud, Cost Optimization

How do you optimize SQS throughput from a Java consumer?

Hard · Cloud, Java & Cloud, SQS

What JVM and container settings matter for Spring Boot on ECS Fargate?

Hard · Cloud, Java & Cloud, ECS

What is Amazon EC2 and when do you use it?

Easy · Cloud, Cloud Fundamentals, Fresher

What is a load balancer and how do health checks work?

Easy · Cloud, Cloud Fundamentals, Fresher

When do you choose SQL (RDS) vs NoSQL (DynamoDB) in the cloud?

Easy · Cloud, Cloud Fundamentals, Fresher

What are containers and Docker, and why do clouds use them?

Easy · Cloud, Cloud Fundamentals, Fresher

What is Kubernetes and why is it used on cloud?

Easy · Cloud, Cloud Fundamentals, Fresher

What is CI/CD and how does it work in cloud deployments?

Easy · Cloud, Cloud Fundamentals, Fresher

How does DNS work in cloud architectures?

Easy · Cloud, Cloud Fundamentals, Fresher

Explain encryption at rest vs in transit in the cloud.

Easy · Cloud, Cloud Fundamentals, Fresher

What is the difference between public and private subnets?

Easy · Cloud, Cloud Fundamentals, Fresher

How do you achieve high availability using multiple Availability Zones?

Easy · Cloud, Cloud Fundamentals, Fresher

What is cloud monitoring and why is it essential?

Easy · Cloud, Cloud Fundamentals, Fresher

What is a message queue and when do you use SQS or Pub/Sub?

Easy · Cloud, Cloud Fundamentals, Fresher

How do you troubleshoot VPC connectivity issues?

Medium · Cloud, Cloud Fundamentals, Fresher

Explain SLI, SLO, and SLA in cloud reliability engineering.

Medium · Cloud, Cloud Fundamentals, Senior

What is Amazon CloudFront and when do you use a CDN?

Easy · Cloud, AWS, Senior

VPC Peering vs Transit Gateway — when to use each?

Medium · Cloud, AWS, Senior

How do VPN and Direct Connect enable hybrid cloud?

Medium · Cloud, AWS, Senior

What is Amazon Cognito and when do you use it?

Medium · Cloud, AWS, Senior

What are AWS Glue and Athena for data analytics?

Medium · Cloud, AWS, Senior

When do you choose Amazon Redshift?

Medium · Cloud, AWS, Senior

What is Amazon ECR and how does it fit in container workflows?

Easy · Cloud, AWS, Fresher

How do AWS Config, GuardDuty, and Security Hub improve security posture?

Medium · Cloud, AWS, Staff

Terraform state management, modules, and drift detection — best practices?

Medium · Cloud, AWS, Senior

How does SAML/OIDC federation work for cloud access?

Medium · Cloud, AWS, Senior

How do you implement FinOps with Cost Explorer, CUR, and budgets?

Medium · Cloud, AWS, Senior

What is BigQuery and when do you use it?

Medium · Cloud, GCP, Senior

How does Apache Beam and Dataflow handle stream and batch processing?

Medium · Cloud, GCP, Staff

What is Cloud Composer and when do you use Airflow?

Medium · Cloud, GCP, Staff

What are VPC Service Controls and how do they protect data?

Hard · Cloud, GCP, Staff

How does Identity-Aware Proxy (IAP) implement zero-trust access?

Hard · Cloud, GCP, Staff

Design a scalable REST API on AWS or GCP.

Medium · Cloud, System Design Scenarios, Senior

Design an event-driven architecture on the cloud.

Medium · Cloud, System Design Scenarios, Senior

Design an e-commerce platform on AWS (catalog, cart, orders, payments).

Medium · Cloud, System Design Scenarios, Senior

Design a cloud-based notification system (email, SMS, push).

Medium · Cloud, System Design Scenarios, Senior

How do you design and test a cloud disaster recovery runbook?

Medium · Cloud, System Design Scenarios, Senior

Design a multi-tenant SaaS application on AWS.

Hard · Cloud, System Design Scenarios, Staff

Design a payment processing system on the cloud.

Hard · Cloud, System Design Scenarios, Staff

Design a global video streaming platform using CDN.

Hard · Cloud, System Design Scenarios, Staff

How do you migrate a production workload to the cloud with zero downtime?

Hard · Cloud, System Design Scenarios, Staff

How do you design an AWS Organization with landing zones and Control Tower?

Hard · Cloud, Cloud Architecture & Strategy, Staff

What is platform engineering and how do you build an Internal Developer Platform (IDP)?

Hard · Cloud, Cloud Architecture & Strategy, Staff

How do you implement chaos engineering on cloud infrastructure?

Medium · Cloud, Cloud Architecture & Strategy, Staff

Explain the strangler fig pattern for cloud migration.

Medium · Cloud, Cloud Architecture & Strategy, Staff

When should an organisation adopt a multi-cloud strategy?

Hard · Cloud, Cloud Architecture & Strategy, Staff

How do you design a cloud data lake architecture?

Hard · Cloud, Cloud Architecture & Strategy, Staff

How do error budgets drive cloud reliability decisions?

Medium · Cloud, Cloud Architecture & Strategy, Staff

When do you use a service mesh (Istio/Linkerd/App Mesh) on cloud?

Hard · Cloud, Cloud Architecture & Strategy, Staff

How do cloud architectures address SOC 2, HIPAA, and PCI compliance?

Hard · Cloud, Cloud Architecture & Strategy, Staff

How do you plan cloud capacity for viral traffic events?

Hard · Cloud, Cloud Architecture & Strategy, Staff

Explain the 6 Rs of cloud migration and the Cloud Adoption Framework.

Medium · Cloud, Cloud Architecture & Strategy, Architect

How do you align enterprise architecture with cloud strategy?

Hard · Cloud, Cloud Architecture & Strategy, Architect

Design a hybrid and multi-cloud architecture for a global enterprise.

Hard · Cloud, Cloud Architecture & Strategy, Architect

How do you establish a FinOps Center of Excellence?

Hard · Cloud, Cloud Architecture & Strategy, Architect

What is a lakehouse and how do you govern data across cloud platforms?

Hard · Cloud, Cloud Architecture & Strategy, Architect

How would you present a 3-year cloud strategy to executive leadership?

Hard · Cloud, Cloud Architecture & Strategy, Architect

Explain unit economics and chargeback models in cloud.

Hard · Cloud, Cloud Architecture & Strategy, Architect

How do you design cloud infrastructure for AI/ML at scale?

Hard · Cloud, Cloud Architecture & Strategy, Architect

How do you design sustainable, carbon-aware cloud workloads?

Medium · Cloud, Cloud Architecture & Strategy, Architect

How do you decide build vs buy for cloud platform capabilities?

Hard · Cloud, Cloud Architecture & Strategy, Architect

Design an enterprise cloud landing zone for 50+ development teams.

Hard · Cloud, Cloud Architecture & Strategy, Architect