list of 25 essential AWS interview questions and answers for experienced professionals, optimized for clarity and technical depth:
Core AWS Services
- Q: Explain the difference between EC2 and Lambda.
A:
- EC2: Virtual servers you manage (persistent, scalable)
- Lambda: Serverless functions (event-driven, auto-scaling, pay-per-execution)
- Q: What is an S3 bucket? How does versioning work?
A:
- S3: Object storage for files
- Versioning: Keeps multiple variants of an object (protects against accidental deletes)
- Q: When would you use RDS vs DynamoDB?
A:
- RDS: SQL/relational data (structured queries)
- DynamoDB: NoSQL (scalable, low-latency key-value store)
Networking & Security
- Q: What is a VPC? Key components?
A:
- Virtual Private Cloud: Isolated AWS network
- Components: Subnets, Route Tables, NACLs, Security Groups
- Q: Explain IAM roles vs policies.
A:
- IAM Role: Temporary credentials for AWS services/users
- IAM Policy: JSON document defining permissions
- Q: How does AWS Shield protect against DDoS?
A:
- Standard: Free layer 3/4 protection
- Advanced: Paid (layer 7 protection + WAF integration)
Scalability & Performance
- Q: What is Auto Scaling? Components?
A:
- Automatically adjusts EC2 capacity
- Components: Launch Configurations, Scaling Policies, Target Groups
- Q: How does ELB differ from ALB/NLB?
A:
- ELB (Classic): Legacy load balancer
- ALB: Layer 7 (HTTP/HTTPS), NLB: Layer 4 (TCP/UDP)
- Q: What is CloudFront? How does caching work?
A:
- CDN for fast content delivery
- Caching: Uses Edge Locations (TTL-based)
DevOps & Automation
- Q: Explain CI/CD pipeline using AWS services.
A:- CodeCommit → CodeBuild → CodeDeploy → CodePipeline
- Alternatives: Jenkins + AWS integrations
- Q: What is CloudFormation vs Terraform?
A:- CloudFormation: AWS-native (YAML/JSON)
- Terraform: Multi-cloud (HCL syntax)
- Q: How does AWS EKS manage Kubernetes?
A:- Managed control plane + worker nodes (EC2 or Fargate)
Database & Storage
- Q: When to use ElastiCache?
A:- Caching layer for high-read applications (Redis/Memcached)
- Q: What is EBS vs EFS?
A:- EBS: Block storage (attached to EC2)
- EFS: File storage (multi-AZ, NFS)
- Q: How does Aurora improve over RDS?
A:- 5x faster, auto-scaling storage, multi-master replication
Advanced Topics
- Q: What is AWS Lambda cold start? How to mitigate?
A:- Delay when Lambda initializes
- Fix: Provisioned Concurrency, smaller packages
- Q: Explain VPC Peering vs Transit Gateway.
A:- Peering: 1:1 connection between VPCs
- Transit Gateway: Hub-and-spoke model
- Q: What is AWS Organizations? Use cases?
A:- Manage multiple AWS accounts
- Use cases: Consolidated billing, SCPs for security
Monitoring & Cost Optimization
- Q: Key differences between CloudWatch and CloudTrail?
A:- CloudWatch: Metrics/logs (performance)
- CloudTrail: API call history (governance)
- Q: How to reduce AWS costs?
A:- Reserved Instances, Spot Instances, S3 lifecycle policies
- Q: What is Trusted Advisor?
A:- AWS tool for cost/security/performance recommendations
Serverless & Containers
- Q: When to use Fargate vs EC2 for ECS?
A:- Fargate: Serverless (no node management)
- EC2: More control (cost-optimized for long-running)
- Q: Explain SQS vs SNS.
A:- SQS: Queue (pull-based)
- SNS: Pub/Sub (push-based)
- Q: What is AWS Step Functions?
A:- Orchestrates Lambda functions (state machines)
Final Question
- Q: How do you secure an AWS environment?A:
- IAM least privilege, encryption (KMS), VPC flow logs, GuardDuty
This list balances fundamental concepts (EC2, S3) with advanced scenarios (multi-account strategies, cost optimization) while keeping answers concise and actionable.
- Titles : 25+ AWS Interview Questions & Answers (2024) – Crack Senior Cloud Roles
- Senior AWS Interview Guide: 25 Technical Questions You Must Prepare
- AWS Cloud Interview Questions 2024: Advanced Level with Detailed Answers
- The Ultimate AWS Interview Cheat Sheet: 25+ Questions for Experienced Professionals
- Top 25 AWS Interview Questions on EC2, Lambda, VPC & More (2024 Update)
- AWS Solutions Architect Interview: 25 Advanced Technical Questions Answered
- 25 Scenario-Based AWS Interview Questions for Senior DevOps Engineers
- AWS Interview Prep 2024: 25+ Questions on Security, Scaling & Cost Optimization
- These 25 AWS Interview Questions Will Separate Junior from Senior Candidates
- The Complete AWS Interview Question Bank (2025): From EC2 to Serverless
- 25 AWS Cloud Interview Questions Every Senior Engineer Should Master in 2025
- For Reddit/Forums: What AWS Concepts Are Actually Asked in Senior Interviews? (25 Q&A)
- For Featured Snippets: What Are the Most Important AWS Interview Questions for Experienced Candidates
TAGS : AWS interview questions, AWS interview questions and answers, AWS technical interview, AWS Solutions Architect interview, AWS cloud engineer questions, AWS 2024 interview prep, Senior AWS interview, AWS DevOps interview, EC2 interview questions, AWS Lambda interview, VPC networking questions, IAM security interview, S3 storage questions, AWS RDS vs DynamoDB, CloudFront CDN interview, AWS Certified Solutions Architect questions, AWS Certified DevOps Engineer prep, AWS SysOps Administrator interview, AWS Cloud Practitioner exam, AWS scaling interview questions, AWS cost optimization interview, AWS serverless architecture questions, AWS disaster recovery interview, AWS multi-account strategy, Professional Networks (LinkedIn):, #AWS, #CloudComputing, #TechInterview, #CloudEngineer, #AWSCertified, Developer Communities (Twitter/Reddit):, #AWSCommunity, #DevOps, #Serverless, #CloudArchitect, #InterviewPrep, Job Seekers:, #CloudJobs, #TechCareers, #GetAWSCertified, #ITInterviews, AWS GenAI interview questions, AWS Bedrock interview prep, Amazon Q business AI questions, AWS Skill Builder interview, AWS vs Azure interview, AWS vs GCP questions, Terraform vs CloudFormation interview, AWS associate-level questions, AWS professional-level interview, AWS expert certification prep