AWS Interview Questions: Crack Your Next Interview in 2025

The AWS platform is a leading supplier of cloud infrastructure, providing networking, storage, and scalable computing services. Its suite of tools is essential for companies located all over the world. AWS is such an integral part of modern-day business through efficacy, flexibility, and security.

In this blog, the main AWS interview questions and answers are featured that candidates should be aware of for this role, be it an AWS solution architect, DevOps engineer, cloud engineer, or data engineer. With this guide, you’ll be covered from the most basic to the most sophisticated level of the content learned, ensuring you have the necessary knowledge to ace interviews and advance in the cloud computing profession.

AWS drives contemporary cloud infrastructure through vital services. This section addresses basic interview questions with answers for freshers to develop understanding, succeed in interviews, and get ready for more complex subjects.

Q1. What is AWS, and why is it so popular?

AWS (Amazon Web Services) delivers scalable cloud computing solutions, providing on-demand infrastructure, tools, and services with worldwide accessibility, usage-based pricing, robust security, and a diverse array of offerings.

Q2. Define and explain the three basic types of cloud services and the AWS products based on them.

The three primary categories of cloud services include Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). AWS offerings consist of EC2 (IaaS), Elastic Beanstalk (PaaS), and AWS WorkDocs (SaaS).

Q3. What is Amazon EC2?

Amazon EC2 provides flexible cloud computing, enabling users to deploy virtual servers and modify resources as required, paying solely for the computing time utilized.

Q4. What is Amazon S3?

Amazon S3 is a service for object storage that allows data storage and access, offering capabilities such as:

• Data durability
• Lifecycle management
• Replication across regions

Q5. What is Amazon VPC?

Amazon VPC enables users to establish isolated network environments in AWS by setting up IP ranges, subnets, and route tables for tailored and secure networking.

Q6. What is AWS Lambda?

AWS Lambda executes code in reaction to events without the need for server administration, automatically scaling and accommodating multiple programming languages.

Q7. What is Elastic Beanstalk?

Elastic Beanstalk streamlines deployment, scaling, and infrastructure management enabling developers to concentrate entirely on coding their applications.

Q8. What is Auto Scaling?

Auto Scaling modifies AWS resource capacity in response to demand. It:

• Guarantees application accessibility
• Lowers expenses by adjusting resource levels as needed
• Facilitates adaptive and forecasting scaling strategies

Q9. What is Amazon RDS?

Amazon RDS streamlines database administration by managing backups, updates, and scaling while supporting various database engines with high availability.

Q10. What is Amazon CloudFront?

Amazon CloudFront provides content through a CDN, enhancing user experience and minimizing server load by utilizing a worldwide network

Q11. What is the purpose of Amazon Route 53?

Amazon Route 53 is a flexible DNS (Domain Name System) service crafted to direct end users to applications. It provides:

• Domain enrollment
• Health assessments and oversight
• Distributing traffic among various resources for enhanced availability and dependability.

Q12. What are AWS Regions and Availability Zones?

AWS Regions are geographical areas that contain several data centres, whereas Availability Zones are separate data centres located within a region. They ensure redundancy, fault tolerance, and high availability for applications.

Q13. What is the AWS Free Tier?

The AWS Free Tier provides restricted no-cost access to services, such as EC2, S3 storage, and monthly Lambda requests.

Q14. What is AWS CloudWatch?

AWS CloudWatch oversees resources and applications by gathering metrics, logs, and events to maintain performance, system wellness, and automation.

Q15. What is the difference between a Security Group and a Network ACL?

A Security Group functions as a virtual firewall, for instance, managing both inbound and outbound traffic, whereas a Network ACL offers stateless traffic filtering at the subnet level.

Q16. What is Amazon DynamoDB?

Amazon DynamoDB is a serverless NoSQL database cloud service fully managed by AWS. It scales to support high availability and low latency for applications like customer reservations.

Q17. What is Amazon SNS and its use case?

Amazon SNS sends notifications between systems through SMS, email, or push notifications for instant alerts and application messaging.

Q18. What is Amazon ElastiCache?

Amazon ElastiCache is a fully managed in-memory caching service that increases application performance by reducing latency and the load on databases.

Q19. What is Amazon Glacier used for?

Amazon Glacier is a low-cost storage service with inexpensive retrieval costs for infrequently accessed data like backups and archives.

Q20. What is Amazon SWF?

Amazon SWF (Simple Workflow Service) coordinates workflows for distributed applications, enabling the monitoring and management of tasks to create dependable, fault-tolerant application processes.

Once you have covered the basics, it’s time to move on to the AWS Interview Questions for Intermediate stage. Questions by this stage get a tad complicated:

Q21. Explain the key components of AWS architecture.

The AWS architecture consists of various components: 

• Compute (EC2, Lambda) Storage (S3, EBS), 
• Database (RDS, DynamoDB), 
• Networking (VPC, Route 53),
• Security (IAM, KMS),
• Monitoring (CloudWatch), 
• Management tools (CloudFormation, Systems Manager) to provide scalable and secure solutions

Q22. What are the different types of storage available in AWS?

AWS offers a variety of storage options:

• Amazon S3: Reliable and scalable storage for objects.
• EBS: Block storage designed for EC2 instances, often used for databases.
• Amazon Glacier: Cost-effective solution for long-term data archiving.
• FSx and EFS: Managed file systems for high-performance applications.

These options allow organizations to choose the most suitable storage solution based on their needs for performance, durability, and budget.

Q23. What is the difference between stopping and terminating an EC2 instance?

Halting an EC2 instance retains its data and settings, enabling it to be restarted later, whereas terminating an instance results in its permanent deletion, along with any linked storage (unless using Amazon EBS). Instances that have been terminated cannot be restarted.

Q24. How does Amazon S3 ensure data durability?

Amazon S3 offers 99.999999999% durability for data as it replicates across multiple availability zones. Data integrity is further enhanced through the use of checksums, along with versioning management and lifecycle management processes, for long-term retention and availability.

Q25. What are the various load balancers provided by AWS?

AWS provides the following types of load balancers:

• Classic Load Balancer (CLB): Basic load balancing for HTTP and TCP traffic.
• Application Load Balancer (ALB): Offers advanced routing capabilities, SSL termination, and WebSocket support.
• Network Load Balancer (NLB): Optimized for handling high-performance TCP and UDP traffic.

These load balancers ensure efficient traffic distribution and application scalability.

Q26. How does Auto Scaling improve performance?

Auto Scaling would automatically increase or decrease the number of EC2 instances involved so that performance and cost are optimally achieved. For example, an e-commerce company could scale up during the sale and then continue to scale down afterwards to reduce costs.

Q27. What is the difference between RDS Read Replicas and Multi-AZ deployments?

Read Replicas are read-only copies of a database, useful for scaling read-heavy applications and offloading workloads like reporting. Multi-AZ deployments, however, provide high availability by creating synchronous replicas in another availability zone, ensuring failover support during outages.

Q28. How can you secure an EC2 instance?

To secure an EC2 instance, you can:

• Use security groups to control inbound and outbound traffic.
• Assign IAM roles to manage API access securely.
• Encrypt data at rest and in transit using AWS KMS and SSL.
• Regularly update and patch the operating system and software.

These measures help protect the instance from security threats.

Q29. What are Amazon S3 lifecycle policies?

S3 lifecycle policies allow you to automate transitions between storage classes or delete objects after a specified period. For instance, a file can stay in Standard S3 storage for 30 days and then move to Glacier for cost efficiency.

Q30. What is the AWS Shared Responsibility Model?

The AWS Shared Responsibility Model states the division of responsibility between the customer and the provider. Thus, AWS looks after the infrastructure, hardware and network security related to the cloud, while clients secure their information, applications and user access.

Q31. How do you implement disaster recovery in AWS?

Disaster recovery in AWS replicates data across regions or availability zones using services like Amazon S3, RDS for database replication, and Route 53 for DNS failover. This helps to ensure that there is little disruption during an outage.

Q32. What are the different types of EBS volumes?

AWS provides several EBS volume types to meet various performance needs:

• General Purpose SSD (gp3): For general-purpose workloads like web hosting.
• Provisioned IOPS SSD (io2): For high-performance applications like databases.
• Throughput Optimized HDD (st1): For large, sequential workloads like data lakes.
• Cold HDD (sc1): For infrequent access, such as logs or archival data.

Q33. What is the difference between vertical and horizontal scaling in AWS?

Vertical scaling involves upgrading the instance size (e.g., t3.medium to t3.large) to handle increased workloads. Horizontal scaling adds more instances (e.g., Auto Scaling groups) to distribute the workload across multiple resources.

Q34. What is AWS CloudFormation, and how does it work?

AWS CloudFormation is an Infrastructure-as-Code (IaC) service that uses templates written in JSON or YAML to provision AWS resources. It automates the deployment and management of resources like EC2, VPC, and RDS, ensuring consistency across environments.

Q35. What is AWS OpsWorks?

AWS OpsWorks is a configuration management service that simplifies the deployment and management of applications using Chef or Puppet. It is especially useful for setting up and managing multi-tier architectures.

Q36. What is the purpose of IAM Roles?

IAM Roles provide temporary permissions to AWS services for trusted entities such as EC2 instances or Lambda functions. Unlike IAM users, roles don’t have permanent credentials, making them ideal for secure, temporary access.

Q37. How do you create a VPC, and what are its components?

Creating a VPC involves specifying an IP range, creating public and private subnets, configuring route tables, and attaching an internet gateway. Components include security groups, network ACLs, and isolated environments for applications.

Q38. What is Amazon EMR, and when should it be used?

Amazon EMR is a big data processing service that uses frameworks like Hadoop and Spark. It is suitable for tasks such as data transformation, machine learning, and log analysis.

Q39. What is AWS Config?

AWS Config tracks and audits changes in AWS resource configurations and relationships. It helps maintain compliance, monitor history, and manage resources effectively.

Q40. How do you optimize costs in AWS?

AWS costs can be optimized by using Reserved Instances for steady workloads, Spot Instances for non-critical tasks, and Auto Scaling to adjust capacity as needed. Tools like AWS Cost Explorer and Trusted Advisor help identify unused resources to reduce expenses.

Here, we cover advanced aws interview question and answers for experienced that assess your deep understanding of AWS architecture, services, and best practices.

Q41. How do you automate EC2 backups using EBS snapshots?

Utilize Amazon Data Lifecycle Manager (DLM) to automate EC2 backups by arranging EBS snapshots, establishing retention policies, and automating the creation and deletion for disaster recovery, such as nightly backups.

Q42. What is the difference between instance store and EBS?

Instance store offers temporary storage linked to an EC2 instance, whereas EBS provides persistent storage that remains after the instance is terminated. EBS is perfect for databases, whereas instance store is appropriate for temporary caching or fast, ephemeral data storage.

Q43. How do you improve database performance in Amazon RDS?

To enhance database performance in Amazon RDS, refine queries, implement indexing, activate Multi-AZ for greater availability, increase storage and compute capabilities, employ read replicas, track with CloudWatch, and use performance insights to pinpoint bottlenecks.

Q44. What is AWS Direct Connect, and how does it work?

AWS Direct Connect creates private network connections between on-premises data centers and AWS, avoiding the public internet to enhance security and decrease latency. For instance, Direct Connect can facilitate the secure transmission of extensive financial data volumes.

Q45. How does Amazon Redshift support data warehousing?

Amazon Redshift is a managed data warehouse service that utilizes columnar storage and compression for rapid queries and optimal storage, allowing businesses to swiftly analyze vast datasets such as local sales information.

Q46. What is AWS Lambda@Edge, and how does it differ from AWS Lambda?

AWS Lambda@Edge executes functions at edge sites nearer to users, decreasing latency, in contrast to traditional AWS Lambda. It’s perfect for worldwide uses, including image scaling or A/B testing. For instance, Lambda@Edge provides quicker processing throughout different regions.

Q47. How can you secure data at rest and in transit in AWS?

Secure stored data by utilizing AWS services such as EBS and S3 encryption. To secure data during transmission, activate TLS/SSL. Protect customer information in Amazon RDS by utilizing Transparent Data Encryption (TDE) and HTTPS for internet traffic.

Q48. What are the best practices for scaling in AWS?

Utilize Auto Scaling groups to modify capacity, Elastic Load Balancing for distributing traffic, and create stateless applications. An online shopping platform expands during Black Friday, guaranteeing peak performance without human involvement.

Q49. How does AWS implement CI/CD pipelines?

AWS utilizes CodePipeline, CodeBuild, and CodeDeploy to automate the processes of building, testing, and deploying. Developers upload code to GitHub, while CodePipeline streamlines the testing and deployment process, guaranteeing smooth updates to production.

Q50. What is the role of AWS Transit Gateway?

AWS Transit Gateway links various VPCs and on-site networks. It consolidates traffic management among VPCs and hybrid settings. Connect VPCs spanning different regions through a single Transit Gateway, streamlining the management of multi-region networks for extensive applications.

Q51. How do you troubleshoot latency issues in an AWS VPC?

To identify the sources of latency, examine VPC flow logs, CloudWatch metrics, and the performance of EC2 networks. Improve by utilizing Enhanced Networking, configuring Security Groups, or altering Route Tables. Instruments such as the VPC Reachability Analyzer assist in detecting misconfigurations.

Q52. What is AWS Trusted Advisor, and how does it help optimize AWS usage?

AWS Trusted Advisor provides instantaneous suggestions for enhancing AWS infrastructure, addressing cost efficiency, security, resilience, performance, and service quotas. It aids in pinpointing underutilized resources, recommends cost-reduction strategies, and guarantees optimal practices for security and efficiency, lowering operational expenses.

Q53. What are Global Tables in DynamoDB?

Global Tables synchronize DynamoDB tables across various AWS regions to enable low-latency access globally. This guarantees high availability, offering worldwide users uniform, dependable data—perfect for applications such as e-commerce that need quick, global data access.

Q54. What is Amazon Neptune, and what use cases is it suited for?

Amazon Neptune is a managed graph database designed for linked data. It is ideal for uses such as recommendation systems, fraud detection, and social platforms, allowing for rapid, real-time graph queries to investigate intricate connections among data points.

Q55. How do you monitor and troubleshoot AWS Lambda performance?

Track Lambda performance through CloudWatch Logs and Metrics. Utilize AWS X-Ray for distributed tracing to detect problems such as resource limitations, timeouts, and misconfigurations by examining function execution durations, error rates, and logs.

Q56. What are S3 pre-signed URLs, and how are they used?

S3 pre-signed URLs provide limited-time access to private S3 files. They are created using AWS SDKs and come with an expiration time. Typical applications involve enabling users to upload or download files while keeping S3 objects private, like in secure file-sharing services.

Q57. How does Amazon Athena work?

Amazon Athena enables SQL queries on Amazon S3 data through Presto, a serverless framework that charges per query. It’s perfect for examining extensive datasets, such as logs, without transferring data or importing it into databases.

Q58. What is the AWS Service Catalog?

AWS Service Catalog assists organizations in developing and overseeing a catalogue of AWS resources. It guarantees uniform configurations and services, ensuring compliance and minimizing manual mistakes. It is utilized for providing predetermined solutions to users.

Q59. What is a blue-green deployment in AWS?

Blue-green deployment uses two identical setups (blue and green) to reduce downtime. Traffic first directs to the blue environment, and after updates, the green environment is activated, facilitating smooth transitions with low risk in AWS Elastic Beanstalk.

Q60. How do you handle serverless application monitoring?

For monitoring serverless applications, utilize AWS X-Ray to trace requests via Lambda and API Gateway, combined with CloudWatch Logs for error and performance tracking. Develop tailored metrics to oversee particular workflows for effective debugging.

You’ve aced the basic, intermediate, and advanced stages. 

But wait, there’s more: AWS S3, a critical service in the AWS ecosystem. Perfect your skills with these most commonly asked AWS S3 interview questions

Q61. What are the different storage classes in Amazon S3?

Amazon S3 provides various storage categories:

• The criterion for regularly retrieved information
• Smart-Tiering for automated expense optimization.
• Glacier and Deep Archive provide long-term storage solutions, with retrieval durations that span from minutes to hours.

Q62. How does S3 handle versioning?

S3 versioning enables a bucket to contain multiple versions of an identical object. When activated, every object update generates a new version that can be accessed or reinstated. It offers safeguards for data against unintentional deletions or overwrites, improving data recovery.

Q63. What is the purpose of S3 Access Points?

S3 Access Points make it easier to manage data access in shared environments. They permit distinct access settings for various users or applications while maintaining security. They are beneficial in multi-tenant settings, offering regulated access according to network or user needs.

Q64. What is cross-region replication in S3?

Cross-region replication (CRR) automatically copies S3 objects across various AWS regions. This offers enhanced data durability, quicker content delivery, and adherence to regulatory data residency standards. It’s beneficial for recovery from disasters and geographical redundancy.

Q65. How can you secure an S3 bucket?

Harden S3 buckets by:

• Activating bucket policies to set access permissions
• Employing IAM roles for regulated access
• Activating Server-Side Encryption (SSE) for safeguarding data
• Implementing MFA Delete to stop unauthorized deletions
• Limiting public access through blocking public access configurations

Q66. What is Amazon S3 Transfer Acceleration?

S3 Transfer Acceleration enhances data transfer rates to and from S3 by routing traffic over AWS's global network of edge locations. It is ideal for uploading large files from remote locations in a shortened time.

Q67. What is the maximum size of an object in S3?

The largest size for a single item that can be uploaded to Amazon S3 is 5 terabytes (TB). For bigger uploads, the object needs to be uploaded in several segments utilizing the Multipart Upload API, which enables effective parallel uploads.

Q68. How do lifecycle policies work in S3?

Lifecycle policies automate the handling of objects in S3. They establish guidelines to move items to less expensive storage classes (such as IA or Glacier) or remove them after a specified duration. For instance, items that are over 30 days old may be transferred to Glacier for storage.

Q69. What is S3 Intelligent-Tiering?

S3 Intelligent-Tiering dynamically moves objects among two access tiers: frequent and infrequent based on usage patterns. This saves storage costs without human intervention, making it ideal for data with unpredictable usage patterns.

Q70. How do you troubleshoot access-denied errors in S3?

Review IAM policies, bucket policies and ACLs for proper permissions. Verify that the requesting party has the proper access privileges and check the correct resource path and actions.

Next, test your knowledge of private subnets, routing, and connectivity across the AWS cloud in this section on the toughest AWS VPC interview questions.

Q71. What are the key components of a VPC?

Essential elements of a VPC consist of:

• Subnets
• Route Tables:
• Internet Gateways
• NAT Gateways
• Security Groups & ACLs
  These elements guarantee safe network administration.

Q72. How do subnets work in a VPC?

Subnets split a VPC’s IP address range into smaller portions. They enable you to segregate resources for security and management. Subnets may be public (reachable through the Internet) or private (separated from the Internet).

Q73. What is the difference between a NAT Instance and a NAT Gateway?

A NAT instance is one EC2 instance utilized to direct traffic from private subnets to the internet. A NAT gateway is a managed solution that provides improved availability, and scalability and eliminates maintenance burden when compared to a NAT instance.

Q74. What are VPC Peering connections?

VPC Peering establishes a link between two VPCs, allowing them to communicate via private IP addresses. It is beneficial for exchanging resources among VPCs in either the same or different regions, yet transitive routing among multiple VPCs is not supported.

Q75. How does a VPC route table work?

A route table in a VPC determines the direction of traffic inside a VPC. It includes paths that define the destination CIDR block and the target (e.g., internet gateway, NAT gateway, VPC peering). 

Q76. What is the purpose of VPC Flow Logs?

VPC Flow Logs collect data regarding network traffic that is sent to and received from network interfaces within a VPC. They assist in identifying network problems, overseeing security, and examining traffic trends for auditing and compliance.

Q77. How do security groups and network ACLs differ?

Security groups are stateful, overseeing traffic at the instance level. Network ACLs are stateless, managing subnet-level traffic through defined allow/deny rules for both incoming and outgoing traffic.

Q78. What is a Transit Gateway in AWS?

A Transit Gateway is a central hub that connects multiple VPCs, on-premises networks, and VPNs to make simple interconnections without the need for complicated peering. It simplifies network design, especially in large, multi-VPC environments.

Q79. What is AWS Direct Connect, and how does it work with VPC?

AWS Direct Connect creates a dedicated, low-latency network link between your on-site data center and AWS. It connects with VPCs to ensure a secure, reliable connection for workloads that demand high bandwidth and low latency.

Q80. How do you troubleshoot VPC connectivity issues?

To troubleshoot VPC connectivity problems, review security group rules, network ACLs, and route tables, and verify that the VPC peering or VPN connection is correctly set up. Moreover, VPC Flow Logs can be utilized to examine traffic and identify problems.

For all aspiring cloud architects and developers, AWS Interview Questions for Database is here: you can’t master AWS without knowing about its powerful managed database services.

Q81. What is Amazon Aurora, and how does it differ from other RDS engines?

Amazon Aurora is a managed relational database that works with MySQL/PostgreSQL, providing superior performance, automatic backups, replication, scalability, and cost-effectiveness in comparison to regular RDS engines.

Q82. What is Amazon DynamoDB, and what are its use cases?

Amazon DynamoDB is a managed NoSQL database that provides excellent performance and minimal latency for applications such as mobile, gaming, and IoT, featuring automated scaling and secure data access.

Q83. How does Multi-AZ improve database availability in RDS?

Multi-AZ in RDS enhances availability by duplicating data to a standby instance located in another Availability Zone, allowing for automatic failover and ongoing application uptime.

Q84. What is Amazon Redshift, and what are its key features?

Amazon Redshift is a flexible data warehousing solution featuring columnar storage, data compression, and parallel query processing, facilitating rapid and effective analysis of large datasets.

Q85. What is ElastiCache, and how does it improve performance?

Amazon ElastiCache is a memory-based data store that stores frequently accessed information, lowering database strain and enhancing response times for real-time applications and high-performance situations.

Q86. What is Amazon DocumentDB used for?

Amazon DocumentDB is a managed NoSQL database that is compatible with MongoDB. It assists applications requiring adaptable data structures, such as content management and real-time analysis.

Q87. How do you implement DynamoDB Streams?

Enable DynamoDB Streams on tables to log changes. Utilize AWS Lambda or Kinesis for immediate processing of data modifications (insertions, updates, deletions).

Q88. What is Amazon Neptune, and what is it used for?

Amazon Neptune is a fully managed graph database designed for storing and querying interconnected information, beneficial for recommendation systems, fraud detection, and knowledge graphs.

Q89. How do database snapshots work in AWS?

AWS database snapshots serve as backups from a specific moment in time. Both automated and manual snapshots can be recovered in Amazon RDS for the purpose of data consistency and recovery.

Q90. How can you monitor database performance in AWS?

Utilize Amazon CloudWatch to monitor metrics such as CPU utilization, disk I/O, and query performance. RDS and Performance Insights offer in-depth, fine-grained performance evaluations.

Understanding the fundamentals of AWS is crucial for success in cloud computing. A comprehensive guide covering critical services like EC2, S3, RDS, and VPC can equip candidates with the confidence to handle various AWS interview scenarios effectively. As more businesses adopt cloud solutions, being an expert in AWS offers numerous career benefits, reduces operational costs, and positions individuals as valuable contributors to the growing cloud ecosystem.

Moreover, investing in AWS training can significantly enhance one's ability to ace AWS interview questions. For instance, courses like those offered by NetCom Learning can provide valuable insights and practical knowledge, helping individuals prepare for AWS certifications and excel in AWS interview questions, thereby increasing their chances of securing cloud-related roles.