AWS Interview Questions

AWS Interview Questions

🟢 Basic Level (1–20)

What is AWS?
What is cloud computing?
What are the main benefits of AWS?
What is EC2?
What is S3?
Difference between EC2 and S3?
What is AWS region?
What is Availability Zone (AZ)?
What is IAM?
What is a root user in AWS?
What is a security group?
What is an AMI?
What is AWS Free Tier?
What is Elastic IP?
What is AWS console?
What is cloud storage?
What is scalability in AWS?
What is high availability?
What is fault tolerance?
What is pay-as-you-go model?

⚙️ Core Services (21–40)

What is AWS Lambda?
What is serverless computing?
What is RDS?
What is DynamoDB?
Difference between RDS and DynamoDB?
What is VPC?
What is subnet?
What is internet gateway?
What is NAT gateway?
What is route table?
What is load balancer?
Types of load balancers?
What is Auto Scaling?
What is CloudFront?
What is AWS CloudWatch?
What is CloudTrail?
What is S3 bucket?
Types of S3 storage classes?
What is EBS?
Difference between EBS and S3?

🔐 Security (41–55)

What is IAM role?
What is IAM policy?
Difference between user and role?
What is MFA in AWS?
What is encryption in AWS?
What is KMS (Key Management Service)?
What is security group vs NACL?
What is least privilege principle?
How does AWS secure data?
What is access key and secret key?
What is AWS Shield?
What is AWS WAF?
What is DDoS attack protection?
What is bucket policy in S3?
How to secure S3 bucket?

🌐 Networking (56–70)

What is VPC peering?
What is VPN connection in AWS?
What is public vs private subnet?
What is elastic load balancing?
What is DNS?
What is Route 53?
What is latency?
What is bandwidth?
What is IP addressing in AWS?
What is hybrid cloud?
What is edge location?
What is CDN?
What is traffic routing?
What is packet filtering?
What is network ACL?

⚡ Advanced (71–90)

What is microservices architecture in AWS?
What is containerization?
What is Docker on AWS?
What is ECS?
What is EKS?
Difference between ECS and EKS?
What is serverless architecture?
What is event-driven architecture?
What is Step Functions?
What is API Gateway?
What is CI/CD in AWS?
What is CodePipeline?
What is CodeBuild?
What is CodeDeploy?
What is infrastructure as code (IaC)?
What is CloudFormation?
What is Terraform vs CloudFormation?
What is monitoring in AWS?
What is logging in AWS?
What is DevOps in AWS?

🚀 Scenario-Based (91–100)

How do you deploy a web app on AWS?
How do you reduce AWS cost?
How do you handle traffic spikes?
How do you make a system highly available?
How do you migrate on-premise to AWS?
How do you secure a REST API on AWS?
How do you troubleshoot EC2 issues?
How do you optimize S3 storage cost?
How do you design scalable architecture?
Why choose AWS over other cloud platforms?

AWS Interview Answers (Q1–Q100 Short Solutions)

🟢 Basic (1–20)

Cloud computing platform by AWS
Delivery of computing services over internet
Scalability, pay-as-you-go, flexibility
Virtual server in cloud
Object storage service
EC2 = compute, S3 = storage
Geographic area of AWS
Isolated data center in region
Identity and access management service
Main AWS account owner
Firewall for EC2
Amazon Machine Image
Free usage tier for beginners
Static public IP
Web-based AWS management UI
Online data storage
Ability to grow system resources
System continues working even after failure
System survives failures
Pay only for usage

⚙️ Core Services (21–40)

Serverless compute service
No server management required
Managed relational database service
NoSQL database service
SQL vs NoSQL database types
Virtual Private Cloud
Subsection of VPC
Connects VPC to internet
Enables private subnet internet access
Controls routing rules
Distributes traffic
ALB, NLB, CLB
Automatically adjusts instances
Content delivery network
Monitoring service
Logs AWS activity
Storage container
Standard, IA, Glacier, etc.
Block storage for EC2
S3 = object, EBS = block storage

🔐 Security (41–55)

IAM identity with permissions
Permission document (JSON)
User = person, Role = temporary access
Extra login security layer
Data protection method
Key management service
SG = instance, NACL = subnet
Minimum required permissions
Encryption + access control
Credentials for API access
DDoS protection service
Web attack protection
Prevents distributed attacks
Rules for S3 access
Block public access + encryption

🌐 Networking (56–70)

Connects two VPCs
Secure private connection
Public = internet access, private = no
Traffic distribution system
Domain name system
DNS service
Delay in response
Data transfer capacity
IP allocation system
On-prem + cloud mix
Edge server location
Content delivery system
Directs traffic flow
Filters network packets
Controls subnet traffic

⚡ Advanced (71–90)

Small independent services system
Packaging apps in containers
Running Docker in AWS
Container service
Kubernetes service
ECS = AWS native, EKS = Kubernetes
No server management architecture
Event-triggered system
Workflow automation service
API management service
Automation of build/deploy
CI/CD pipeline tool
Build automation tool
Deployment automation tool
Code infrastructure
Infrastructure as code tool
Terraform is multi-cloud
System monitoring
Log tracking
Development + operations model

🚀 Scenario (91–100)

Use EC2 + S3 + load balancer
Use reserved instances, optimize usage
Use auto scaling + load balancer
Multi-AZ deployment
Use AWS migration tools
Use IAM + API Gateway + JWT
Check logs, security groups
Use lifecycle policies
Use VPC + scaling + microservices
Better scalability + services + global reach