Are you looking to build a career in cloud computing or data? Then, learning AWS is a must-have skill for you. Almost every cloud-related job like cloud developer, cloud architect, solution architect, cloud security engineer or DevOps engineer, requires AWS proficiency. Then what are you waiting for? Prepare with the most asked AWS interview questions and answers with this guide and land your first cloud computing job.
Whether you are a beginner or a seasoned professional, these AWS interview questions and answers are all you need. It covers every concept from the very basic to the most advanced.
The different types of instances in Amazon EC2 are-
VPC in Amazon refers to a Virtual Private Cloud. This is the most apt way to connect to a company's cloud resources from its own data center. Once the VPC containing all the instances is connected to the data center, a private IP address is assigned to each of them. These IP addresses can be accessed from the company's data center. This allows the organization to access its public cloud resources, as though they are on its private network.
SnowBall is an application that aids in transferring humongous amounts of data to and from the AWS cloud. Secured physical storage is used by this application for transferring the data. Being a petabyte-scale data transportation solution, SnowBall aids in saving time and cost.
Amazon RDS
Since Amazon S3 is a REST service, a request can be sent via the REST API, or the AWS SDK wrapper libraries.
In this cloud technology, key pairs refer to secure login info for our virtual machines. Key pairs containing a private key and a public key can be used for connecting to the instances.
The major key components are-
Here are the differences-
| S3 | EC2 |
| Amazon S3 is a data storage system that facilitates storing any amount of data. | EC2 is a cloud web service that is used to host the application. |
| S3 has a REST interface & utilized secure HMAC-SHA1 authentication keys. | EC2 is like a gigantic computer machine that can run on both Windows & Linux. It can also handle apps like Apache, PHP, Python & other databases. |
Yes, Amazon instances can be vertically scaled with these steps-
A few connection issues that most possibly arise while connecting to an instance include -
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AMI or Amazon Machine Image is a template that allows launching N number of instances from it. AMI provides all integral information for launching an instance. An AMI includes -
In case of multiple VPN connections, AWS VPN CloudHub can be used to instill secure communication between sites.
We use the classic load balancer for simple load balancing of traffic throughout various EC2 instances. On the contrary, we use an application load balancer for more intelligent load balancing, structured on the container-based or multi-tier architecture of the app.
CodePipeline refers to a continuous delivery service that is used for automating, modeling, and visualizing the steps necessary for releasing software. This facilitates rapidly modeling and configuring the various stages involved in the software release process. With CodePipeline, we can automate the steps for releasing the software changes continuously.
CodeStar refers to a cloud-based service that aids in managing, working, and creating software development projects on the cloud platform. With the CodeStar project, we can swiftly build, deploy, and develop apps on cloud platform. Additionally, it facilitates creation and integration of this cloud technology into the project development toolchain.
CodeBuild refers to a completely managed build service in the cloud. CodeBuild does a lot of things, including compiling the source code, running unit tests, and producing artifacts that are ready to be deployed. With CodeBuild, the need to manage, scale, and provision our own build servers is eliminated.
CodeDeploy refers to a service that facilitates in automating code deployments to any instance. This includes instances that are running on-premises and even Amazon EC2 instances. With CodeDeploy, deploying new releases is easier, aiding in avoiding downtime during deployment.
Lambda is a serverless computing service that lets developers execute codes without requiring the provision or maintenance of servers. It executes the code in a continuous infrastructure and performs administrations of compute resources.
Developers use it for operating and server system maintenance, automatic scaling, capacity provisioning, automatic scaling and logging. They just have to supply their program in one of the runtime languages that Lamba supports. Then it will automatically run that code when needed. Hence, they only need to pay-on-use, providing them cost optimization.
The following are some of the most common use areas of this service -
CloudFormation is basically an IaC (Infrastructure as Code) service. It allows experts to perform the following tasks -
OpsWorks is a configuration management service for customizing and operating applications within a cloud enterprise by using Chef or Puppet. This service is no longer available and has been permanently disabled for new and old customers. So, there is no use of this service these days.
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The main difference between these instances relies on their pricing structure. Spot instances use spare capacity, resulting in significant cost savings. But there is a risk of interruption while using this instance. Reserved instances, on the other hand, are relatively cheaper due to their long-term commitment but require upfront payment and a fixed capacity. On-demand instances have a flexible pricing structure where users can predict hourly costs.
I have managed the following IAM categories -
Both of these are data processing techniques, which differ in their approach, use, and nature of data, etc. Here are some of the differences between them. These will help to choose the most efficient technique for a given task.
| Aspects | Batch Processing | Real-Time (Stream) Processing |
| Data Nature | Large, static datasets | Continuous, dynamic streams |
| Processing Style | Scheduled, periodic | Continuous, immediate |
| Latency | High (minutes, hours, days) | Low (milliseconds, seconds) |
| Data Volume | Large, finite | Potentially infinite |
| Timing | Delayed | Immediate |
| Use Cases | Reporting, data warehousing, payroll, bulk updates. | Fraud detection, real-time analytics, IoT monitoring, live streaming. |
| Complexity | Lower | Higher |
| Cost | Generally lower | Generally higher |
| Error Handling | Easier can reprocess entire batch. | More complex, requires fault tolerance. |
| Scalability | Scalable horizontally for large batches. | Scalable horizontally for high throughput streams. |
An operational data store is a core database that can extract real-time data from multiple stores to support operational reporting and decision-making. It acts as a bridge between transactional systems and data warehouses. It provides a clean, consistent and up-to-date snapshot of operational data to the data warehouse. This way developers can perform faster and more informed decision-making.
Amazon S3 provides multiple storage classes for different use cases and cost requirements. The table given below summarizes them -
| Storage Class | Use Case | Access Frequency | Cost |
| S3 Standard | Frequently accessed data | Frequent | Highest |
| S3 Intelligent-Tiering | Data with unknown/changing patterns | Variable | Variable |
| S3 Standard-IA | Infrequently accessed data | Infrequent | Lower |
| S3 One Zone-IA | Infrequently accessed, non-critical data | Infrequent | Lowest (of IA classes) |
| S3 Glacier Instant Retrieval | Long-term archive, immediate retrieval | Very Infrequent | Low archive cost |
| S3 Glacier Flexible Retrieval | Long-term archives | Rare | Very Low |
| S3 Glacier Deep Archive | Long-term archives, rarely accessed | Very Rare | Lowest |
Snapshots in Amazon Lightsail is a service that can restore data or resources when required. It is a paid service, which means you have to pay for each use. Snapshots contain all the data available in a resource when it was taken. We can use it to reconstruct the resource just like the previous one and recover a disk and its data. There are four types of snapshots available in Lightsail including -
Marketplace is an online catalog service provided by Amazon Web Services. It gives a list of third-party software, data and services to use in Amazon Web Services. Using it, one can discover and procure different solutions from Amazon Web Services' partners with easy billing and licensing. This facilitates fast development and simplified management.
Direct Connect is another service of this cloud computing platform. We can use this service to establish a direct connection between data stores and platforms. This network will be way better, more reliable and consistent than the Internet. Direct Connect is mostly preferable in sensitive workloads, large data transfer and low latest connections.
Snowball is a service that can share humongous amounts of data with ease and high speed. This service uses an external device to perform the data transfer. It can transfer information in both directions (in and out).
Assume we have to share 2 TB of data to S3 but the Internet connection is slow (1MB/sec). This might take hours of time to share the complete database. In this case, we have to use an external device like a disk as shown in the image given below -
This requires enabling versioning at the bucket level, which allows us to store multiple versions of the same objects. Every new object upload or modification creates a new version with a unique version ID. These versions are then used to recover the actual object in case of deletions or modifications. We can enable it through AWS Management Console, AWS CLI or AWS SDKs.
When using the console navigate to your S3 bucket > go to the Properties tab > and then click Versioning to enable it.
We can also aerate it using the CLI command -
aws s3api put-bucket-versioning --bucket <bucket-name> --versioning-configuration Status=Enabled |
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It is not possible to change the Private IP Address of an EC2 instance. A private IP Address is given to the EC2 instance when it is launched and is permanent. We have to create a new instance to shift the Private IP Address.
I would use the Amazon Simple Email Service (Amazon AES) to achieve this requirement.
I will use the Multipart Upload Utility to upload this data to Amazon S3. This utility uses a unique approach to process humongous amounts of data. This approach involves partitioning data into multiple parts and uploading them individually. We can also upload these parts in parallel, reducing the overall uploading time. After uploading all the parts, the Multipart Upload Utility combines all of them and makes a single identity.
I will prefer DynamoDB in this situation as it provides great scalability and fast performance. Therefore, it can create a table that can contain any amount of data and manage extensive traffic. Its databases can also scale up and down as per requirements, which makes it innovative and cost-effective. Its ability to distribute the data and traffic to many servers is another reason to choose this database.
Monitoring of this cloud technology requires a comprehensive strategy that involves a combination of different services and third-party tools. But if I had to choose only one service, it would be CloudWatch. Here are the reasons -
Designing a disaster recovery plan includes considering various factors like creating backups, replication of important data, using different strategies and more. It will start from creating a backup of the entire app data across multiple regions. It is also important to specify recovery point objectives (RPO) and Recovery time objectives (RTO).
Next, I will use different services including AWS Elastic Disaster Recovery (EDR) and AWS Backup. They can help to centralize backup management and automate cross-region replication. I will also check plan and application services frequently, such as AWS Disaster Recovery Testing (DRT) to secure the readiness.
I will use AWS Lambda functions in situations they are ideal for. These are mostly useful in situations where serverless, event-driven architecture is required. It follows the principle of pay-as-you-go for billing. For instance, a photo-sharing application could use the Lambda functions. It will be triggered whenever the user uploads an image. They will resize the image, update the metadata, and send the notifications to users.
One of the easiest ways to perform this operation is to set up an auto scaling group to deploy additional instances. Therefore, whenever the CPU use exceeds 80%, it will allocate traffic across different instances by creating an application load balancer.
I would use the following techniques -
I will prefer to use the AWS Elastic Beanstalk in situations where quick app deployment and administration are essential. Elastic Beanstalk facilitates load balancing, capacity provisioning and automatic scaling. This helps to streamline web application deployment. It also provides simple application upgrades, management, monitoring with support of different programming languages and CloudWatch.
Here is a clear breakdown of the core differences between a Security Group (SG) and a Network Access Control List (NACL) in AWS:
| Feature | Security Group (SG) | Network ACL (NACL) |
| Scope | Operates at the instance level (EC2). | Operates at the subnet level. |
| Default Behavior | Stateful - return traffic is automatically allowed regardless of inbound rules. | Stateless - return traffic is always allowed by outbound rules. |
| Rules Applied To | Only allow rules (you cannot explicitly deny traffic). | Can have allow and deny rules. |
| Rule Evaluation | Evaluates all rules before allowing traffic. | Evaluates rules in order of rule number from lowest to highest. Stops at the first match. |
| Direction of Rules | Separate inbound and outbound rule sets. | Separate inbound and outbound rule sets. |
| Default Association | Each EC2 instance is always associated with a minimum one SG. | Each subnet automatically has a default NACL. |
| Typical Use Case | Control access to and from specific instances (application-level control). | Provide broad subnet-level filtering for additional network-layer security. |
Here is a clear breakdown of the three main EC2 pricing models in AWS:
| Pricing Model | How It Works | Cost | When to Use |
| On-Demand | Pay per hour or per second (depending on instance type) with no long-term commitment. | Highest cost per hour but most flexible. | Short-term, unpredictable workloads. Development/testing environments. When you ca not predict workload duration or usage. |
| Reserved Instances (RI) | Commit to 1-year or 3-year term in exchange for significant discounts (up to 72%) compared to On-Demand. | Lower cost, but requires upfront commitment. | Predictable, steady workloads. Always-on production servers. Long-term applications with consistent usage. |
| Spot Instances | Bid for unused EC2 capacity at up to 90% discount. Can be interrupted with 2 minutes' notice if AWS needs the capacity back. | Lowest cost, but not guaranteed availability. | Fault-tolerant workloads. Big data processing, batch jobs. Testing large-scale workloads cheaply. |
Ensuring high availability and fault tolerance for an application on AWS involves:
Here is a quick comparison between Amazon RDS, DynamoDB and Redshift, along with their use cases:
| Feature / Purpose | Amazon RDS | DynamoDB | Amazon Redshift |
| Database Type | Relational | NoSQL | Data Warehouse |
| Ideal For | OLTP apps | Real-time key-value lookups | OLAP analytics |
| Data Structure | Structured | Semi/Unstructured | Structured (Columnar) |
| Query Language | SQL | DynamoDB API (or PartiQL) | SQL |
| Scaling | Vertical + Read Replicas | Automatic horizontal scaling | Scales by adding nodes |
| Example Use Case | Banking DB | Gaming sessions | Sales analytics |
So, in this guide we have discussed the frequently asked questions. Additionally, you can focus on core services, real-world scenarios, and hands-on practice to make preparation strong. Stay updated, explore case studies, and refine problem-solving skills to stay ahead.
To prepare for an interview, you must divert all your focus and attention towards it. Since the field is quite huge, you must be prepared to answer all sorts of questions. Be certain of where your strengths lie and get your interviewer to focus on those. Go through as many interview questions as you can.
EC2 stands for Amazon Elastic Compute Cloud.
The full form of S3 is Amazon Simple Storage Service.
The main services include EC2, S3, RDS, IAM and VPC. These services support compute, storage, security and networking needs.
Yes, AWS is easy for freshers to learn. With regular practice, the basics become easy to understand.
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