- Diverse Question Types – Includes technical, scenario-based, and behavioral questions to assess both knowledge and problem-solving skills.
- Real-World Focus – Questions are designed to reflect actual AWS use cases, helping professionals tackle on-the-job challenges effectively.
- Certification & Interview Ready – Covers AWS fundamentals, best practices, and troubleshooting to prepare for exams and job interviews.
Did you know that 94% of enterprises already use cloud services, with AWS leading the market at 32%? The cloud revolution is no longer a trend—it’s the backbone of modern IT infrastructure. From startups to Fortune 500 companies, organizations rely on AWS for scalability, security, and innovation. But with great demand comes fierce competition. Whether you're preparing for a high-stakes AWS interview, pursuing a sought-after AWS certification, or simply honing your cloud expertise, understanding the right questions can be a game-changer. This guide is more than just a list of questions—it’s a roadmap designed to sharpen your problem-solving skills, challenge your technical knowledge, and help you think like an AWS architect. With insights from industry experts, real-world scenarios, and must-know concepts, you’ll be well-equipped to navigate the cloud computing landscape with confidence
AWS Fundamentals & Core Concepts
1. What is AWS, and how does it work?
AWS is a cloud computing platform offering computing, storage, and networking services on a pay-as-you-go model.
Example: Hosting a website using EC2 and S3.
2. Explain the AWS Global Infrastructure.
AWS consists of Regions, Availability Zones (AZs), and Edge Locations for global coverage.
Example: Deploying an app in the US-East-1 region for better latency.
3. What is the AWS Shared Responsibility Model?
AWS secures infrastructure, while users manage data, access, and configurations.
Example: AWS protects EC2 servers, but users must configure firewall rules.
4. What are the key benefits of using AWS?
Scalability, cost-efficiency, security, high availability, and flexibility.
Example: Auto-scaling EC2 instances based on traffic demand.
5. How does AWS pricing work?
Pay-as-you-go pricing with On-Demand, Reserved, and Spot Instances.
Example: Using Spot instances based on traffic demand.
6. What is the difference between AWS Regions and Availability Zones?
Regions are separate geographic areas; AZs are multiple data centers within a region.
Example: Deploying in us-west-1 for US customers, ensuring HA with multiple AZs.
7. Explain AWS Free Tier and its limitations.
Free for 12 months, includes limited usage of EC2, S3, Lambda, RDS.
Example: Running a t2.micro EC2 instance with 750 hours/month free.
8. What is an AWS Service Level Agreement (SLA)?
AWS guarantees uptime and availability, offering credits for downtime.
Example: 99.99% uptime SLA for EC2; if breached, credits are issued.
9. What are AWS Edge Locations?
Data centers used by CloudFront for content caching, reducing latency.
Example: Serving a video stream faster from an Edge Location in London.
10. How does AWS provide high availability?
Using Multi-AZ, auto-scaling, load balancing, and failover strategies.
Example: RDS Multi-AZ replication ensures database uptime.
Compute Services
11. What is Amazon EC2?
Virtual servers in the cloud with scalable resources.
Example: Running a WordPress site on an EC2 instance.
12. What are the different EC2 instance types?
General, Compute-Optimized, Memory-Optimized, Storage-Optimized, GPU.
Example: Using c5.large for compute-heavy workloads.
13. What is EC2 Auto Scaling?
Automatically adjusts the number of instances based on demand.
Example: Increasing EC2 instances during high traffic spikes.
14. Explain Elastic Load Balancing (ELB) and its types.
Distributes traffic across instances; ALB (Layer 7), NLB (Layer 4), CLB (legacy).
Example: ALB for routing requests based on URL path.
15. What is AWS Lambda?
Serverless compute service that runs code in response to events.
Example: Running a thumbnail generator on S3 file uploads.
Storage & Database Services
16. What is Amazon S3?
Scalable object storage for files, backups, and media.
Example: Storing user profile images for a web app.
17. What are the different storage classes in S3?
Standard, IA, Glacier, Glacier Deep Archive.
Example: Storing old logs in S3 Glacier for cost savings.
18. What is Amazon RDS?
Managed relational database service supporting MySQL, PostgreSQL, etc.
Example: Running a high-traffic e-commerce database.
19. What is Amazon DynamoDB?
Serverless NoSQL database with millisecond latency.
Example: Running a real-time chat messages in a mobile app.
20. How do you enable encryption in Amazon S3?
Use SSE-S3, SSE-KMS, or SSE-C for encryption.
Example: Encrypting sensitive customer data using SSE-KMS.
21. What is an AWS Storage Gateway?
A hybrid storage service that connects on-premises environments to AWS cloud storage.
Example: Using File Gateway to back up local files to Amazon S3.
22. What is Amazon Elastic File System (EFS)?
A scalable, managed NFS (Network File System) for Linux workloads.
Example: Sharing app data between multiple EC2 instances.
23. How do you migrate a database to AWS?
Use AWS DMS (Database Migration Service) for seamless migration.
Example: Moving a MySQL database from on-prem to Amazon RDS.
24. What is Amazon FSx?
A managed file storage service for Windows (FSx for Windows) and high-performance computing (FSx for Lustre).
Example: Running a Windows file server in AWS.
25. How do you optimize database performance in AWS?
Use indexes, read replicas, caching (ElastiCache), and proper instance sizing.
Example: Using read replicas to distribute RDS query load.
Network & Security
26. What is Amazon VPC?
A private network to launch AWS resources.
Example: Hosting secure internal applications inside a VPC.
27. What is an Elastic IP?
A static public IP assigned to an EC2 instance.
Example: Assigning a fixed IP for SSH access.
28. What is AWS Direct Connect?
A dedicated connection between AWS and on-prem data centers.
Example: Using Direct Connect for secure data transfer.
29. What is AWS Route 53?
A scalable DNS service for domain name resolution.
Example: Pointing mywebsite.com to an EC2 instance.
30. What is AWS CloudFront?
A content delivery network (CDN) for caching.
Example: Accelerating image delivery for global users.
31. Your web application is experiencing high latency for global users. How would you reduce latency?
- Deploy AWS CloudFront for caching static assets.
- Use AWS Global Accelerator for optimized network routing.
- Enable RDS read replicas in multiple regions.
Example: Reducing API response time for users in Asia using Global Accelerator.
32. A critical AWS resource was deleted accidentally. How would you investigate and prevent such issues in the future?
- Check AWS CloudTrail logs for API actions.
- Restore from AWS Backup or S3 Versioning.
- Use IAM permissions to restrict deletions.
Example: Preventing accidental S3 bucket deletion using bucket policies.
31. Your web application is experiencing high latency for global users. How would you reduce latency?
- Deploy AWS CloudFront for caching static assets.
- Use AWS Global Accelerator for optimized network routing.
- Enable RDS read replicas in multiple regions.
Example: Reducing API response time for users in Asia using Global Accelerator.
33. Your team suspects unauthorized access to an EC2 instance. How would you detect and prevent security breaches?
- Use Amazon GuardDuty to detect threats.
- Check VPC Flow Logs for unusual traffic.
- Enable IAM roles instead of access keys.
Example: Detecting unauthorized SSH access and blocking the IP via Security Groups.
34. Your application requires secure communication between EC2 instances across different VPCs. How would you achieve this?
- Use VPC Peering for direct connections.
- Deploy AWS Transit Gateway for centralized routing.
- Use Site-to-Site VPN if on-premises is involved.
Example: Connecting finance and analytics VPCs via Transit Gateway.
35. A client requests a private, highly available DNS resolution for internal applications. What AWS service would you use?
- Use Route 53 Private Hosted Zones.
- Ensure VPC association for internal access.
Example: Providing private DNS for an internal microservices architecture.
36. Your company's compliance policy requires all internet traffic to pass through an AWS firewall. How would you implement this?
- Deploy AWS Network Firewall for deep packet inspection.
- Use AWS WAF to block malicious traffic.
- Enforce routing via NAT Gateway & Firewall Manager.
Example: Blocking unauthorized outbound traffic using AWS Firewall Manager.
37. You need to configure a multi-VPC architecture with centralized security controls. How would you approach this?
- Use AWS Transit Gateway for inter-VPC communication.
- Implement AWS Security Hub & AWS Firewall Manager for compliance.
Example: Managing security policies across multiple VPCs with a Transit Gateway.
38. Your team needs to allow temporary access to an S3 bucket for an external user. How would you manage permissions?
- Use pre-signed URLs for time-limited access.
- Assign temporary IAM roles with limited access.
Example: Granting a partner read-only access to a report via pre-signed URLs.
Serverless & Containers
39. How does AWS Lambda handle concurrency?
Scales automatically to handle multiple executions.
Example: Processing thousands of image uploads simultaneously.
40. What is AWS Fargate?
Serverless container service for running ECS/EKS workloads.
Example: Deploying a microservices app without managing EC2.
41. How do you deploy a containerized application on AWS?
Use ECS, EKS, or Fargate.
Example: Running a Node.js API inside an ECS cluster.
42. What is an AWS Lambda layer?
A way to reuse dependencies across Lambda functions.
Example: Sharing Python libraries across multiple Lambdas.
43. What is AWS Step Functions?
A service for orchestrating workflows between AWS services.
Example: Handling order processing in an e-commerce app.
44. How does AWS Lambda handle concurrency?
Lambda automatically scales by spawning multiple instances.
Example: Handling 10,000 user requests simultaneously.
45. What are the key components of AWS Lambda?
- Function Code: The logic that executes.
- Event Source: Triggers (S3, API Gateway, DynamoDB, etc.).
- Execution Role: IAM permissions.
Example: A Lambda function triggered by S3 file uploads.
46. What is AWS Fargate?
A serverless container service that eliminates EC2 management.
Example: Running a Docker-based microservice without managing servers.
47. What is Amazon ECS?
A container orchestration service that manages Docker containers.
Example: Running a Python API service inside an ECS cluster.
48. How does Amazon EKS differ from ECS?
- ECS: Uses AWS-proprietary orchestration.
- EKS: Runs Kubernetes-managed containers.
Example: Using EKS for Kubernetes-based applications.
49. What is AWS App Runner?
A fully managed service for running containerized apps.
Example: Deploying a Node.js web app without managing infrastructure.
50. What is AWS Step Functions?
A workflow orchestration service for automating AWS tasks.
Example: Processing user registrations across multiple services.
51. How do you troubleshoot AWS Lambda cold starts?
- Increase memory allocation.
- Use provisioned concurrency.
- Optimize package size.
Example: Reducing Lambda cold start time from 3s to 500ms.
52. How do you deploy a containerized application on AWS?
Use ECS, EKS, or Fargate to deploy Docker containers.
Example: Running a Spring Boot microservice on ECS.
53. What is an AWS Lambda layer?
A shared library for reusing code across multiple Lambda functions.
Example: Using a Lambda layer to share database connectors.
Monitoring & Logging
54. What is AWS CloudWatch?
A monitoring service for logs, metrics, and alerts.
Example: Tracking CPU usage of EC2 instances.
55. How do you set up CloudWatch alarms?
Define thresholds for metrics, trigger actions when exceeded.
Example: Alerting when disk usage exceeds 80%.
56. What is AWS CloudTrail?
Logs all API activity for auditing.
Example: Tracking who deleted an S3 bucket.
57. What is AWS X-Ray?
Helps debug distributed applications.
Example: Tracing latency issues in a serverless app.
58. How do you analyze AWS logs?
Use CloudWatch Logs Insights or Athena.
Example: Querying error logs from Lambda.
59. What is AWS CloudWatch?
A monitoring service for logs, metrics, and events in AWS.
Example: Tracking CPU usage of EC2 instances.
60. How do you set up CloudWatch alarms?
Define thresholds for metrics and trigger actions when exceeded.
Example: Sending email alerts if disk usage exceeds 80%.
61. What is AWS CloudTrail?
Logs all API activity for auditing and security monitoring.
Example: Identifying who deleted an S3 bucket.
62. What is AWS X-Ray?
A service for debugging and tracing requests in distributed applications.
Example: Analyzing latency issues in a serverless app.
63. How do you monitor AWS Lambda logs?
Using CloudWatch Logs and AWS X-Ray for real-time insights.
Example: Viewing Lambda execution errors in CloudWatch.
64. What are AWS Trusted Advisor recommendations?
Provides best practice recommendations on cost, security, and performance.
Example: Suggesting unused EC2 instances for cost savings.
65. What is Amazon GuardDuty?
A threat detection service for monitoring security anomalies.
Example: Detecting unauthorized API calls from an attacker.
66. How does AWS Config help with compliance?
Tracks AWS resource changes and compliance with security policies.
Example: Alerting when S3 bucket access is set to public.
67. What is AWS EventBridge?
A serverless event bus for connecting AWS services and third-party apps.
Example: Triggering a Lambda function on new S3 file uploads.
68. How do you analyze AWS logs?
Using CloudWatch Logs Insights, Athena, or OpenSearch.
Example: Searching for failed login attempts in IAM logs.
Networking & Content Delivery
69. What is Amazon VPC?
A private, isolated network within AWS for launching resources securely.
Example: Deploying web and database servers in separate subnets.
70. What is an Elastic IP?
A static, public IP assigned to an AWS resource, typically an EC2 instance.
Example: Keeping the same public IP for a web server after instance reboot.
71. Explain AWS Direct Connect.
A dedicated network connection from on-premises to AWS for better bandwidth and security.
Example: Using Direct Connect to transfer large datasets securely.
72. What is AWS Route 53?
A scalable DNS (Domain Name System) service for domain management.
Example: Routing www.example.com traffic to an EC2 instance.
73. What is AWS CloudFront?
A content delivery network (CDN) for caching and accelerating content delivery.
Example: Serving videos globally with lower latency.
74. How does AWS Global Accelerator work?
Optimizes traffic routing across AWS Regions for better performance.
Example: Reducing latency for global users of a web application.
75. What is the difference between a public and private subnet in AWS?
Public Subnet: Has internet access via Internet Gateway.
Private Subnet: No direct internet access, used for internal workloads.
Example: Placing a database server in a private subnet.
76. What is a NAT Gateway?
Allows instances in a private subnet to access the internet securely.
Example: Enabling a private EC2 instance to download OS updates.
77. Explain AWS Transit Gateway.
Connects multiple VPCs and on-prem networks for centralized management.
Example: Linking multiple departments’ VPCs in an enterprise.
78. How does AWS handle DDoS protection?
Using AWS Shield, WAF (Web Application Firewall), and CloudFront.
Example: AWS Shield mitigates DDoS attacks on a gaming website.
Security & Compliance
79. What is AWS IAM?
Manages user access, roles, and permissions for AWS resources.
Example: Granting S3 read-only access to a user.
80. What are IAM roles and policies?
IAM Roles: Temporary permissions assigned to AWS resources.
IAM Policies: JSON-based rules defining permissions.
Example: Assigning an IAM role to an EC2 instance for S3 access.
81. How does AWS Key Management Service (KMS) work?
Encrypts data using managed encryption keys.
Example: Encrypting database records in Amazon RDS.
82. What is AWS Shield?
A DDoS protection service that mitigates attacks automatically.
Example: Protecting a web app from large-scale attacks.
83. What is AWS WAF?
A Web Application Firewall that filters malicious traffic.
Example: Blocking SQL injection attacks on a website.
84. What is AWS Security Hub?
A security monitoring service aggregating AWS security findings.
Example: Detecting open security vulnerabilities in EC2.
85. How does AWS CloudHSM work?
A dedicated hardware security module (HSM) for encryption key management.
Example: Using CloudHSM for regulatory compliance encryption.
86. How does AWS handle compliance requirements?
Through audit logs, encryption, and security policies.
Example: Enabling CloudTrail logs for GDPR compliance.
87. What is AWS Artifact?
A repository of AWS compliance reports and security certifications.
Example: Downloading SOC 2 compliance reports.
88. Explain AWS Organizations.
A tool for managing multiple AWS accounts centrally.
Example: Enforcing billing and security policies across departments.
DevOps & CI/CD
89. What is AWS CodePipeline?
A fully managed CI/CD service that automates code deployments.
Example: Automating deployment of a Node.js application from GitHub to EC2.
90. What is AWS CodeBuild?
A managed build service for compiling source code, running tests, and creating packages.
Example: Compiling a Java application before deploying to Lambda.
91. Explain AWS CodeDeploy.
Automates deployments to EC2, Lambda, and on-premises environments.
Example: Rolling out a new API version to multiple EC2 instances.
92. How does AWS CodeCommit work?
A fully managed Git repository for version control.
Example: Storing Terraform scripts for infrastructure automation.
93. What is AWS CloudFormation?
An Infrastructure-as-Code (IaC) service for automating AWS resource provisioning.
Example: Deploying a VPC, EC2, and RDS using a YAML template.
94. What is AWS Elastic Beanstalk used for?
A PaaS (Platform as a Service) for deploying web applications without managing infrastructure.
Example: Hosting a Python Flask application on AWS.
95. What is AWS OpsWorks?
A configuration management service using Chef and Puppet for automating infrastructure setup.
Example: Automating server updates for a high-traffic website.
96. How does AWS handle CI/CD automation?
Using CodePipeline, CodeBuild, and CodeDeploy for continuous integration and delivery.
Example: Automating React app deployments to S3 and CloudFront.
97. What is AWS SAM (Serverless Application Model)?
A framework for building, testing, and deploying serverless applications.
Example: Deploying a Lambda-based API with SAM templates.
98. How does AWS handle Blue/Green deployments?
AWS shifts traffic between two environments (old and new) to minimize downtime.
Example: Deploying a new version of a web app without disrupting users.
Big Data & Analytics
99. What is Amazon Athena?
A serverless query service for analyzing S3 data using SQL.
Example: Running SQL queries on access logs stored in S3.
100. How does AWS Glue work?
A serverless ETL (Extract, Transform, Load) service for data preparation.
Example: Cleaning and transforming customer transaction data.
101. What is Amazon Kinesis?
A service for real-time data streaming and processing.
Example: Analyzing stock price changes in real-time.
102. What is AWS Data Pipeline?
A service for automating data movement and processing.
Example: Transferring RDS data to Redshift for analytics.
103. How does Amazon QuickSight work?
A BI (Business Intelligence) tool for visualizing AWS data.
Example: Creating sales trend dashboards for marketing teams.
104. What is AWS Lake Formation?
Helps build, secure, and manage data lakes in AWS.
Example: Organizing IoT sensor data in a centralized lake.
105. What is the difference between Kinesis Data Streams and Firehose?
- Data Streams: Real-time processing with manual consumer setup.
- Firehose: Fully managed streaming that auto-loads data into S3, Redshift, or Elasticsearch.
Example: Using Kinesis Data Streams for real-time log analysis.
106. What is AWS EMR?
A managed Hadoop & Spark cluster for big data analytics.
Example: Running machine learning models on large datasets.
107. How do you optimize AWS Redshift performance?
Using distribution keys, compression, and query optimization.
Example: Using columnar storage for faster data retrieval.
108. What is Amazon OpenSearch Service?
A managed search and analytics engine (formerly Elasticsearch).
Example: Searching logs from millions of web requests.
Machine Learning & AI
110. What is Amazon SageMaker?
A fully managed machine learning (ML) service for building, training, and deploying ML models.
Example: Training a fraud detection model on SageMaker.
111. How does AWS Rekognition work?
An AI service that analyzes images and videos for facial recognition and object detection.
Example: Detecting faces in security camera footage.
112. What is AWS Lex?
A conversational AI service that builds chatbots and voice assistants using NLP.
Example: Creating a customer support chatbot.
113. What is AWS Polly?
A text-to-speech (TTS) service that converts text into natural speech.
Example: Generating audio versions of blog posts.
114. What is AWS Transcribe?
An AI-based speech-to-text service that converts audio into written text.
Example: Transcribing customer service call recordings.
115. What is AWS Comprehend?
A Natural Language Processing (NLP) service for sentiment analysis, entity recognition, and topic modeling.
Example: Analyzing social media sentiment.
116. How does AWS Fraud Detector work?
Uses ML to detect fraudulent transactions based on user activity patterns.
Example: Identifying unusual credit card transactions.
117. How does AWS Inferentia improve ML workloads?
A custom ML inference chip that speeds up model inference while reducing costs.
Example: Running image classification models faster.
118. What is AWS Personalize?
A recommendation engine for personalized user experiences using ML.
Example: Suggesting movies on a streaming platform.
119. How do you deploy a trained ML model in AWS?
Using SageMaker Endpoints, Lambda, or Fargate for inference.
Example: Deploying a price prediction model via SageMaker.
AWS Hybrid & Edge Services
120. What is AWS Outposts?
A hybrid cloud solution that extends AWS infrastructure to on-prem data centers.
Example: Running low-latency applications on-premises with AWS services.
121. How does AWS Snowball work?
A physical data transport device for transferring large amounts of data to AWS.
Example: Migrating 100TB of video archives to S3.
122. What is AWS Wavelength?
A service that brings AWS compute to 5G networks for ultra-low latency applications.
Example: Running real-time gaming servers on 5G networks.
123. What is AWS Local Zones?
Extends AWS compute and storage closer to users in specific metro areas.
Example: Reducing latency for video editing workflows.
124. What is AWS Direct Connect?
A dedicated network link between AWS and on-premises environments for secure, high-speed data transfer.
Example: Connecting corporate data centers to AWS.
125. How do you migrate on-prem workloads to AWS?
Using AWS Migration Hub, Snowball, or DMS (Database Migration Service).
Example: Moving an on-prem SQL database to Amazon RDS.
126. What is AWS Ground Station?
A managed satellite communication service for receiving and processing satellite data.
Example: Collecting weather data from satellites.
127. How does AWS handle hybrid cloud networking?
Using VPC Peering, Transit Gateway, Direct Connect, and VPN.
Example: Connecting on-prem networks with AWS via Direct Connect.
128. What is AWS Storage Gateway?
A hybrid storage service that connects on-prem storage with the AWS cloud.
Example: Backing up local files to Amazon S3.
129. What are AWS Snowmobile and its use cases?
A truck-sized data transfer service for exabyte-scale migrations.
Example: Transferring large-scale enterprise data centers to AWS.
AWS Best Practices & Troubleshooting
130. What is the AWS Well-Architected Framework?
A set of best practices to build secure, high-performing, resilient, and efficient cloud architectures.
Example: Reviewing a microservices architecture for security improvements.
131. What are the five pillars of AWS Well-Architected Framework?
- Operational Excellence – Automate and monitor operations.
- Security – Implement strong identity management and data protection.
- Reliability – Design for failure recovery.
- Performance Efficiency – Optimize workloads.
- Cost Optimization – Reduce unnecessary costs.
Example: Designing a multi-region deployment strategy.
132. What are the best practices for AWS security?
- Use IAM roles and least privilege access.
- Enable MFA for user authentication.
- Encrypt data at rest and in transit.
Example: Applying IAM policies to restrict S3 access.
133. How do you troubleshoot EC2 performance issues?
- Check CPU, memory, and disk usage in CloudWatch.
- Analyze network latency and I/O bottlenecks.
- Use autoscaling if under high demand.
Example: Upgrading an EC2 instance type to handle more traffic.
134. How do you handle AWS service limits?
- Monitor usage with Service Quotas.
- Request limit increases from AWS Support.
Example: Requesting a higher EC2 instance limit for a scaling project.
135. How do you optimize AWS cost?
- Use Reserved Instances & Spot Instances.
- Enable Auto Scaling and Idle Resource Termination.
- Use S3 Lifecycle Policies.
Example: Moving cold storage data to S3 Glacier.
136. What are some AWS design patterns?
- Event-driven architecture (Lambda + SQS).
- Microservices (ECS/EKS).
- Serverless workflows (Step Functions).
Example: Building a real-time order processing system.
137. What are AWS best practices for microservices?
- Use API Gateway for service communication.
- Implement container orchestration (ECS/EKS).
- Separate databases per microservice.
Example: Deploying a multi-service e-commerce app with ECS.
138. What is an AWS Landing Zone?
A pre-configured multi-account setup for secure cloud adoption.
Example: Setting up centralized logging and IAM policies.
139. What are the benefits of AWS Multi-Account Strategy?
- Isolation of workloads for security and compliance.
- Cost tracking and management per account.
- Better resource governance with AWS Organizations.
Example: Creating separate AWS accounts for dev, staging, and production.
Compute & Auto Scalling
140. Your EC2 instance is running slow. How would you diagnose and improve its performance?
- Check CloudWatch CPU, Memory, and Disk I/O metrics.
- Upgrade to a larger EC2 type if needed.
- Enable Auto Scaling for dynamic resource allocation.
Example: Upgrading t3.micro to m5.large for CPU-intensive workloads.
141. Your application runs on EC2 and experiences sudden traffic spikes. How would you scale the infrastructure dynamically?
- Use Auto Scaling Groups with a scaling policy.
- Deploy an Application Load Balancer (ALB).
Example: Scaling EC2 instances from 2 to 10 during Black Friday sales.
142. An EC2 instance has suddenly stopped responding. How would you troubleshoot and recover it?
- Check CloudWatch logs & instance status.
- Restart the instance if needed.
- Attach the volume to another EC2 instance to investigate logs.
Example: Recovering corrupted EC2 instance logs using EBS mount.
143. A batch processing job is running on EC2 but is taking longer than expected. What steps would you take to optimize it?
- Use Spot Instances for cost savings.
- Optimize disk I/O with high-performance EBS volumes.
Example: Upgrading from gp2 EBS to io1 EBS for faster IOPS.
144. Your application needs to run short-lived processes with minimal costs. Would you use EC2, Lambda, or another service? Why?
- Lambda is best for event-driven, short-lived tasks.
- Fargate is better for containerized workloads.
Example: Using Lambda for thumbnail generation instead of EC2.
145. You need to migrate a traditional application to AWS. How would you decide between EC2, Lambda, and Elastic Beanstalk?
- EC2 for full control.
- Elastic Beanstalk for automatic deployments.
- Lambda for event-driven apps.
Example: Moving a legacy Django app to Elastic Beanstalk.
Storage & Data Management
146. Your S3 bucket needs to store critical data, but access should be restricted to a specific VPC. How would you configure this?
- Use VPC Endpoints for private access.
- Set IAM bucket policies to limit access.
Example: Allowing only private subnet EC2 instances to access S3.
147. An application is experiencing slow read times from an S3 bucket. How would you optimize retrieval performance?
- Enable S3 Transfer Acceleration.
- Use CloudFront caching.
Example: Serving large media files faster with CloudFront.
148. You accidentally deleted important files from an S3 bucket. How can you recover them?
- Use S3 Versioning to restore previous versions.
- Recover data from AWS Backup if enabled.
Example: Restoring a deleted database snapshot stored in S3.
149. You need to move large files between AWS accounts. What is the best approach?
- Use AWS DataSync for bulk data transfer.
- Enable cross-account IAM roles for S3 access.
Example: Migrating TBs of log files securely between AWS accounts.
150. Your RDS database is experiencing high read latency. How would you improve performance?
- Use Read Replicas for read-heavy workloads.
- Implement ElasticCache (Redis/Memcached) for caching.
Example: Reducing query latency by 70% using ElasticCache.
151. Your RDS database needs to be highly available across multiple regions. How would you set this up?
- Use Amazon Aurora Global Database for cross-region replication.
- Enable RDS Multi-AZ.
Example: Running a multi-region e-commerce database.
152. You need to archive infrequently accessed data at a low cost. What AWS service(s) would you use?
S3 Glacier / Deep Archive for long-term storage.
Example: Storing 10-year-old compliance records in Glacier.
153. A DynamoDB table is experiencing high latency on queries. How would you optimize its performance?
- Use DAX (DynamoDB Accelerator).
- Implement Global Secondary Indexes (GSI).
Example: Optimizing product search speeds with GSI indexing.
154. You need to store logs in S3 but ensure that they are immutable. What is the best way to do this?
- Enable S3 Object Lock (WORM).
- Set up Bucket Policies for write-once permissions.
Example: Securing financial audit logs with S3 Object Lock.
Serverless & Event-Driven Architectures
155. Your Lambda function runs slower than expected. What optimizations can you apply?
- Increase memory allocation (it improves CPU performance).
- Enable Provisioned Concurrency to prevent cold starts.
- Reduce package size using Lambda Layers.
Example: Reducing API processing time from 2s to 500ms by increasing memory.
156. Your Lambda function needs to process large payloads exceeding the default limit. How would you handle this?
- Store large payloads in S3 and pass the reference to Lambda.
- Use AWS Step Functions to split processing.
Example: Storing user-uploaded PDFs in S3 instead of passing them to Lambda.
157. A serverless application is experiencing throttling issues in API Gateway. How would you fix this?
- Increase API Gateway request limits.
- Implement Rate Limiting & WAF rules.
- Use DynamoDB Auto Scaling to handle load increases.
Example: Preventing excessive API calls from crashing a checkout system.
158. Your serverless workflow involves multiple AWS services. How would you implement an event-driven architecture?
- Use AWS Step Functions for sequential tasks.
- Utilize EventBridge for cross-service event routing.
- Integrate SQS & SNS for decoupling services.
Example: Processing e-commerce orders with SQS and Step Functions.
159. You need to trigger an AWS Lambda function based on file uploads in S3. How would you set this up?
- Configure S3 Event Notifications to trigger Lambda.
- Use EventBridge for more control over event filtering.
Example: Generating thumbnails from uploaded images in real-time.
160. Your event-driven application is experiencing delays. How would you debug and optimize event processing?
- Enable AWS X-Ray to trace event execution time.
- Monitor Lambda invocation metrics in CloudWatch.
- Optimize SQS message processing.
Example: Identifying slow Lambda execution via AWS X-Ray tracing.
161. You need to ensure that a Lambda function executes only once per event. How would you achieve idempotency?
- Use DynamoDB conditional writes to check event uniqueness.
- Implement deduplication with SQS FIFO.
Example: Preventing duplicate order processing by using unique transaction IDs.
DevOps, CI/CD & Monitoring
162. Your deployment pipeline failed, and the new release is causing downtime. How would you roll back quickly?
- Use AWS CodeDeploy Blue/Green Deployment.
- Restore the previous version from AWS Backup.
Example: Rolling back a failed app update by switching traffic to a stable release.
163. Your team wants to automate infrastructure provisioning. How would you decide between AWS CloudFormation and Terraform?
- CloudFormation: Best for AWS-native automation.
- Terraform: Best for multi-cloud environments.
Example: Using Terraform to manage both AWS and Azure infrastructure.
164. Your production environment is experiencing unexpected performance drops. What monitoring tools would you use to investigate?
- Use CloudWatch Metrics & Alarms for performance insights.
- Analyze AWS X-Ray traces for application bottlenecks.
Example: Detecting high memory usage in Lambda via CloudWatch Logs.
165. You need to deploy code updates to a large number of EC2 instances with minimal downtime. What AWS service would you use?
- Use AWS CodeDeploy Rolling Updates.
- Leverage Blue/Green Deployments.
Example: Rolling out a new app version across 50 EC2 instances without downtime.
166. Your team wants to enable canary deployments for a serverless application. How would you achieve this in AWS?
- Use AWS Lambda Alias Traffic Shifting in CodeDeploy.
- Gradually roll out changes using API Gateway Stages.
Example: Sending 5% of traffic to a new Lambda version before full release.
167. Your CloudWatch logs indicate high memory usage in your EC2 instances. How would you troubleshoot and fix this?
- Identify memory-hungry processes using CloudWatch Metrics.
- Upgrade EC2 instance type or enable Auto Scaling.
Example: Switching from t3.micro to r5.large for memory-intensive apps.
168. Your company requires detailed logging and auditing for all AWS API activities. How would you implement this?
- Enable AWS CloudTrail for API activity tracking.
- Use AWS Security Hub for centralized compliance monitoring.
Example: Detecting unauthorized S3 bucket deletions via CloudTrail logs.
169. Your AWS infrastructure experiences unexpected downtime. How would you investigate and implement failover solutions?
- Check AWS Health Dashboard for service outages.
- Use Multi-AZ & Multi-Region Failover strategies.
Example: Redirecting Route 53 DNS to a standby region during downtime.
Cost Optimization & Performance
170. Your AWS bill has unexpectedly increased. How would you analyze and reduce costs?
- Check AWS Cost Explorer for usage trends.
- Identify and shut down idle EC2, RDS, and EBS volumes.
- Use Savings Plans or Reserved Instances for predictable workloads.
Example: Reducing costs by switching unused EC2 instances to Spot Instances.
171. You need to optimize the cost of a data-intensive application running on AWS. What strategies would you use?
- Use S3 Intelligent-Tiering for storage.
- Implement data compression and deduplication.
- Use Spot Instances for batch processing.
- Optimize queries in Redshift or Athena.
Example: Saving 30% on storage by enabling S3 Lifecycle Policies for infrequent data.
AWS Scenario-Based & Behavioral Questions
172. How would you migrate a monolithic application to AWS?
- Rehost (Lift & Shift): Move it to EC2 with RDS.
- Replatform: Use Elastic Beanstalk for easier management.
- Refactor: Convert into microservices using ECS or Lambda.
Example: Migrating a Spring Boot app from on-prem to ECS with Fargate.
173. How do you design a highly available architecture on AWS?
- Use Multi-AZ RDS and Auto Scaling EC2.
- Distribute traffic via Application Load Balancer (ALB).
- Use CloudFront for content caching.
Example: Deploying a multi-region API with RDS Multi-AZ and ALB.
174. What steps would you take if an AWS service is down?
- Check AWS Health Dashboard and CloudWatch Logs.
- Use multi-region redundancy.
- Ensure failover routing with Route 53.
Example: Redirecting traffic to a secondary region using Route 53 failover.
175. How would you troubleshoot network latency in AWS?
- Check VPC Flow Logs and CloudWatch Metrics.
- Use AWS Global Accelerator for optimized routing.
- Implement CloudFront CDN.
Example: Resolving slow API response times by enabling API Gateway caching.
176. Can you design a scalable e-commerce solution using AWS?
- EC2 Auto Scaling for frontend.
- RDS Multi-AZ for database.
- S3 + CloudFront for media storage.
Example: Deploying a Shopify-like store with Auto Scaling and DynamoDB.
177. How do you optimize AWS Lambda execution time?
- Increase memory allocation.
- Enable Provisioned Concurrency to reduce cold starts.
- Optimize dependencies with Lambda layers.
Example: Reducing API response time by optimizing Lambda package size.
178. Describe a situation where you had to optimize AWS costs.
- Moved infrequent data to S3 Glacier.
- Switched EC2 On-Demand instances to Spot Instances.
Example: Cutting database costs by migrating from RDS to Aurora Serverless.
179. How do you manage infrastructure as code in AWS?
- Use AWS CloudFormation or Terraform.
- Automate deployments with AWS CodePipeline.
Example: Managing VPC, EC2, and RDS using CloudFormation templates.
180. How do you secure an AWS environment for a financial company?
- Use IAM least privilege policies and MFA.
- Encrypt all data with AWS KMS.
- Enable CloudTrail logging for audits.
Example: Implementing PCI-DSS compliance with AWS Shield and IAM restrictions.
181. How would you deploy a multi-region application in AWS?
- Use Route 53 latency-based routing.
- Deploy Aurora Global Database for cross-region replication.
- Use CloudFront to serve global content.
Example: Running a multi-region SaaS product with global users.
Basic Level Behavioral Questions
183. Have you ever faced a situation where you had to explain a complex technical concept to a non-technical person?
- Used real-world analogies to simplify concepts.
- Avoided technical jargon.
- Provided visual aids and diagrams.
Example: Explaining AWS Auto Scaling using a restaurant staffing analogy.
184. How do you manage multiple tasks when working on AWS projects?
- Used JIRA or Trello for task tracking.
- Prioritized based on impact and urgency.
- Automated repetitive tasks using AWS Lambda and scripts.
Example: Managing multiple EC2 migrations while implementing a new CI/CD pipeline.
185. Describe a time you made a mistake in cloud deployment. How did you resolve it?
- Acknowledged the mistake.
- Rolled back using versioned infrastructure (CloudFormation/Terraform).
- Implemented automated testing and approval workflows.
Example: Accidentally deleting an S3 bucket and restoring it via AWS Backup.
Advanced Level Behavioral Questions
186. Have you ever faced an issue with an AWS service in production? How did you handle it?
- Checked AWS Health Dashboard for service status.
- Applied failover mechanisms (Multi-AZ, Route 53 failover).
- Notified stakeholders and implemented a postmortem.
Example: Resolving an RDS downtime issue by switching to a Multi-AZ replica.
187. Tell us about a time when you optimized cloud costs for a project.
- Identified underutilized resources via AWS Cost Explorer.
- Moved static assets to CloudFront for caching.
- Implemented S3 lifecycle policies.
Example: Reducing EC2 and RDS costs by 40% using Auto Scaling and Reserved Instances.
188. Describe a situation where you had to troubleshoot a major performance issue in AWS.
- Analyzed CloudWatch metrics for CPU, Memory, and IOPS usage.
- Scaled resources dynamically with Auto Scaling.
- Used AWS X-Ray to trace slow API calls.
Example: Fixing a high-latency API by enabling DynamoDB On-Demand Capacity Mode.
189. Have you ever had to defend your AWS architecture decisions to stakeholders? How did you do it?
- Backed decisions with data and cost analysis.
- Presented security and scalability benefits.
- Used TCO (Total Cost of Ownership) calculations.
Example: Justifying why migrating to Fargate was more cost-effective than EC2.
190. Explain a time when you led an AWS migration or transformation project.
- Assessed existing on-prem workload.
- Designed a phased migration plan.
- Ensured minimal downtime using AWS DMS.
Example: Migrating a monolithic app to a serverless architecture using AWS Lambda and API Gateway.
Professional Level Behavioral Questions
200. Describe a complex AWS architecture you designed and how it benefited the organization.
- Designed a highly available multi-region architecture.
- Used Microservices on ECS with ALB and RDS Multi-AZ.
- Implemented event-driven data processing with SQS and Lambda.
Example: Enabling a global e-commerce platform with auto-scaled backend services.
201. Have you ever led a team in adopting AWS best practices? What challenges did you face?
- Standardized IAM least privilege access.
- Automated infrastructure deployment using Terraform.
- Educated team members via AWS workshops.
Example: Implementing Well-Architected Framework reviews for all projects.
202. How do you handle conflict when different teams have opposing views on an AWS solution?
- Facilitated a data-driven discussion.
- Used proof-of-concept (POC) testing.
- Considered cost, security, and scalability trade-offs.
Example: Resolving a conflict between serverless vs. containerized approach for a new app.
203. Tell us about a time when you proposed a cloud strategy that significantly impacted business operations.
- Recommended moving compute-heavy tasks to Spot Instances.
- Migrated data warehousing from RDS to Redshift for better analytics.
- Implemented CDN caching to improve web app speed.
Example: Reducing costs by 50% and improving performance with a new AWS cloud strategy.
204. Describe an instance where you mitigated a major AWS security risk.
- Detected an open S3 bucket via AWS Security Hub.
- Enabled IAM role-based access instead of static credentials.
- Used AWS Config to enforce compliance policies.
Example: Preventing data exposure by enforcing S3 encryption and public access block policies.
As AWS continues to shape the future of cloud computing, staying ahead of the curve requires more than just memorizing services—it demands critical thinking, hands-on expertise, and the ability to adapt to a rapidly evolving ecosystem. According to Gartner, cloud spending is projected to reach $679 billion by 2025, making AWS skills not just valuable but essential for IT professionals. Mastering AWS isn’t just about acing an interview or passing a certification—it’s about positioning yourself for long-term success in an industry that thrives on innovation. The questions and insights in this guide are designed to push you beyond the basics, helping you develop a mindset that aligns with AWS best practices and real-world problem-solving. So, keep questioning, keep experimenting, and continue refining your AWS expertise—because the cloud is only getting bigger, and the opportunities are limitless.