AWS Job Assessment Q/A (Part 1)

In this blog, you will find essential AWS Interview Preparation Questions & Answers.

If you are planning for a job switch in AWS and wondering what questions are currently trending? We have compiled a list of the most selective and realistic AWS interview questions to guide you.

At K21Academy, we have curated the top questions frequently asked in interviews, based on current job trends, to help you crack your AWS interviews with confidence. This blog will walk you through critical questions and answers, ensuring you are well-prepared for your assessments. Whether you are a seasoned professional or a newcomer to AWS, our carefully chosen questions will give you the edge you need to succeed in your AWS job interviews.

Q1: The website has just edited its landing page. Most users complain that they cannot view the updated content. What is the possible reason for content not being displayed? Select two options.

1. The users are not getting fresh content due to the unavailability of DNS resolver
2. CDN invalidation process is not added or does not perform its function.
3. The browser still displays the cached content to users. The cache contains old content.
4. The backend database may have inconsistencies.

Correct Option: 2, 3

Reason for each option:

• DNS resolver: wrong

A problem with the DNS resolver wouldn’t prevent users from seeing updated content. It would prevent them from accessing the website entirely because the DNS couldn’t translate the website address (URL) into the server’s IP address.

• CDN Invalidation: correct

Content Delivery Networks (CDNs) store website content on geographically distributed servers for faster loading times. When a website updates content, the CDN cache needs to be invalidated for that specific content so it fetches the new version from the origin server. If invalidation isn’t set up or doesn’t work properly, users served by the CDN keep seeing the old content.

• Browser Cache: correct

Browsers cache website files to improve loading speed. When a website updates its content, especially the landing page, the cached version in the browser becomes outdated. Users continue to see this obsolete version because their browsers haven’t downloaded the new content yet.

• Backend Database Inconsistencies: wrong

While inconsistencies in the backend database could lead to issues with how the updated content is displayed, it wouldn’t necessarily prevent users from seeing it altogether. There might be display errors or missing information, but some form of the updated content would likely be visible.

Q2: The Recovery Time Objective of an application for an organization is 2 hours, and the recovery point objective is 1 hour. The application fails at 9:00 am but is restored at the company’s data recovery site at 10:30 am the same day. The data from 8:00 is restored. Which statement is true for RTO and RPO?

1. RTO was successful, and RPO was not achieved.
2. Both RTO and RPO did not satisfy the standard.
3. RTO was not achieved, and RPO was successful.
4. Both RTO and RPO qualified the standard.

Correct Option: 4

Key Point: RTO focuses on downtime (how long the system is unavailable), while RPO focuses on data loss (how much data is lost after a failure).

Reason for each option:

• RTO was successful, and RPO was not achieved: Incorrect

There was no data loss (achieved RPO), and the downtime also fell within the allowed window (achieved RTO).

• Both RTO and RPO did not satisfy the standard: Incorrect

This is incorrect because RPO successfully recovered data within the acceptable range.

• RTO was not achieved, and RPO was successful: Incorrect

This is the opposite of what happened. The downtime of 1.5 hours is within the RTO target.

• Both RTO and RPO qualified for the standard: Correct

RTO (Recovery Time Objective) achieved: The application failed at 9:00 am and was restored at 10:30 am. The downtime is 1.5 hours, which falls within the target downtime of 2 hours (RTO).

RPO (Recovery Point Objective) achieved: Data was restored at 8:00 am. This means there was no data loss compared to the application failure at 9:00 am. The organization’s acceptable data loss is 1 hour (RPO), and they successfully recovered data within that time frame.

Q3: What do you understand by a LAMP stack?   

1. Linux, Apache, MongoDB, and Python.
2. Linux, Apache, MySQL, and PHP.
3. Lambda, Apache, MongoDB and Python.
4. Lambda, Amplify, MySQL, and Python.

Correct Option: 2

Reason for each option:

• LAMP is an acronym that stands for the four key components used to build and run web applications: Incorrect

L – Linux: This is the operating system that provides the foundation for the entire stack. It’s a free and open-source operating system known for its stability and flexibility.

A – Apache HTTP Server: This is the web server software that processes incoming requests from users’ browsers and delivers the content of the web application. Apache is a popular choice due to its reliability and performance.

M – MySQL: This is the relational database management system (RDBMS) used for storing and managing the application’s data. MySQL is a popular open-source database solution that offers a robust and scalable way to handle web application data.

P – PHP: This is the scripting language most commonly used for developing the dynamic functionality of web applications within the LAMP stack. PHP code can interact with the database to retrieve and manipulate data, and then generate HTML content to be displayed in the user’s browser.

• Linux, Apache, MongoDB, and Python: Correct

While Linux, Apache, and Python are all valid components for web development, MongoDB is a different type of database (NoSQL) not typically used in the LAMP stack.

• Lambda, Apache, MongoDB and Python: Incorrect

Lambda refers to a serverless computing service from AWS, not part of the traditional LAMP stack. Amplify is another AWS service for building mobile and web applications, also not part of LAMP.

• Lambda, Amplify, MySQL, and Python: Incorrect 

Lambda and Amplify are AWS services, not components of the LAMP stack. The LAMP stack is based on open-source software used for hosting dynamic websites and web applications, while Lambda and Amplify are used for serverless computing and web/mobile application development, respectively, which do not fit the traditional LAMP architecture.

Q4: A company is using a synchronous replication process between its data centers. What primary objective does the company want to achieve, particularly for RTO and RPO?

1. Curtail RTO and RPO.
2. Curtail RTO with no impact on RPO.
3. Curtail RPO with no impact on RTO.
4. Augment RTO and RPO.

Correct Option: 1

Key Point:

RTO (Recovery Time Objective) refers to the maximum acceptable amount of time to restore the function after a disruption.

RPO (Recovery Point Objective) refers to the maximum acceptable amount of data loss measured in time.

Reason for each option:

• Curtail RTO and RPO: Correct Answer

Synchronous replication ensures that every write to the primary storage is immediately replicated to the secondary storage before the transaction is considered complete. This means there is no data loss (RPO is nearly zero) because the secondary storage always has the latest data.

Recovery Time Objective (RTO) is also minimized because the secondary storage is already up-to-date with the primary storage. If a failure occurs, the system can quickly switch to secondary storage with minimal downtime.

Therefore, synchronous replication helps significantly reduce both RTO and RPO.

• Curtail RTO with no impact on RPO: Incorrect Answer

Synchronous replication impacts both RTO and RPO. It doesn’t just curtail RTO; it also reduces RPO since the data is always current on both primary and secondary storages.

• Curtail RPO with no impact on RTO: Incorrect Answer

Synchronous replication ensures that data is consistently updated in both primary and secondary locations, which indeed curtails RPO. However, it also affects RTO because, in the event of a failure, the system can quickly switch to the secondary site with minimal downtime. Therefore, saying it has no impact on RTO is incorrect.

• Augment RTO and RPO: Incorrect Answer

“Augment RTO and RPO,” is wrong because augmenting means to increase or make something greater. In the context of disaster recovery and data replication, the primary goal is to reduce (curtail) the Recovery Time Objective (RTO) and the Recovery Point Objective (RPO). Synchronous replication ensures that data is replicated in real-time to another data center, which helps minimize data loss (low RPO) and ensures quick recovery (low RTO) in case of a failure.

Q5: Which two statements are TRUE for the web service communication protocols? Select two options.

1. SOAP only allows XML format, whereas REST has different data formats.
2. SOAP web services and RESTful web services are entirely stateful.
3. REST and SOAP are web service communication protocols.
4. Rest only works with JSON, whereas SOAP is a protocol that only works with XML.

Correct Options: 1, 3

Read More at SOAP Vs REST API | Soap vs Rest Web Services

Reason for each option:

• SOAP and Data Formats: Correct 

SOAP (Simple Object Access Protocol) is designed specifically to use XML for exchanging data between web services. It defines a strict structure for messages with specific tags and attributes.

• SOAP web services and RESTful web services are entirely stateful: Incorrect

This statement is not true. SOAP web services can be either stateful or stateless, depending on the implementation. RESTful web services are typically stateless, which means each request from a client contains all the information needed for the server to fulfill that request.

• REST and SOAP are web service communication protocols: Correct

Both REST (Representational State Transfer) and SOAP are protocols that define how web services communicate with each other. They establish rules and standards for data exchange, allowing different applications to interact.

• Rest only works with JSON, whereas SOAP is a protocol that only works with XML: Incorrect

While it is true that SOAP only works with XML, it is not true that REST only works with JSON. REST can work with multiple formats, including JSON, XML, HTML, and others. JSON is commonly used with REST due to its simplicity and ease of use, but it is not exclusive to it.

Q6: You have prepared and decided on a migration plan of 150 on-site applications by rehosting them to the cloud via the lift and shift method or strategy for your organization. What benefits do you think this strategy will have for your organization? Select two options.

1. Instant and easy migration.
2. Hosting cost reduction for the long term.
3. Ensures Analytics.
4. Minimizes Migration costs.

Correct Options: 1, 4 

Reason for each option:

• Instant and easy migration: Correct

The lift-and-shift method, also known as rehosting, involves moving applications to the cloud with little or no modification. This approach allows for a faster and simpler migration process compared to other methods that require extensive re-architecting or refactoring of applications.

• Hosting cost reduction for the long term: Incorrect

While lift and shift might not immediately reduce costs due to potential licensing changes for cloud usage, it can be a stepping stone to long-term cost reduction. Once the applications are in the cloud, you can explore opportunities to optimize resource usage and potentially benefit from economies of scale offered by cloud providers. However, immediate cost reduction isn’t a guaranteed benefit of lift and shift.

• Ensures Analytics: Incorrect

The lift-and-shift method itself does not inherently ensure analytics capabilities. While migrating to the cloud can facilitate access to advanced analytics tools and services, simply lifting and shifting applications does not automatically integrate them with analytics solutions. This requires additional setup and configuration.

• Minimizes Migration Costs: Correct

Because the lift-and-shift method does not require significant changes to the applications, it tends to have lower initial migration costs. The effort and resources needed for modifying or optimizing applications are minimized, reducing the overall cost of the migration process.

Q7: What would be your response to a customer’s question about why customers should use Network Address Translation (NAT)?

1. Increasing network bandwidth via a single device.
2. Encrypted traffic flows between hosts.
3. Private IP address space conservation.
4. Maximize network security by keeping internal addressing private.

Correct Option: 4

Reason for each option:

• Increasing network bandwidth via a single device: Incorrect

NAT operates at the network layer, translating IP addresses. It doesn’t directly manipulate bandwidth, which is a physical limitation of your internet connection.

• Encrypted traffic flow between hosts: Incorrect

NAT does not inherently provide encryption. While NAT can be part of a network that uses encrypted communication protocols (such as VPNs or HTTPS), NAT itself is not responsible for encrypting traffic.

• Private IP address space conservation: Incorrect

NAT allows multiple devices on a local network to share a single public IP address when accessing the internet. This is crucial for conserving the limited number of public IP addresses, especially given the exhaustion of IPv4 addresses. NAT enables the use of private IP addresses within a local network, which can be reused across different networks without conflict.

• Maximize network security by keeping internal addressing private: Correct

This statement holds some truth. By hiding internal IP addresses from the public internet, attackers can’t directly target specific devices within your network. However, it’s not a complete security solution:

Limited Protection: NAT only masks internal addresses. Malicious actors can still exploit vulnerabilities in software or user behavior (phishing emails) to gain access to your network.

Bypassing NAT: Advanced attackers may use techniques to bypass NAT and reach internal systems if they gain access through other means (infected devices, compromised passwords).

Q8: Which option from the following will likely ensure the minimum transfer time in migrating 10 PB data from one data center to another in a diverse geographical location or continent?

1. It would help if you had a new and dedicated internet connection for the data migration.
2. Store the data to an external device and transport it via airship.
3. Transfer the compressed data files via FTP on the internet.
4. Transfer the encrypted and compressed data via the VPN connection.

Correct Option: 2

Read More at Cloud Migration Strategy

Reason for each option:

• It would help if you had a new and dedicated internet connection for the data migration: Incorrect

Even with a dedicated internet connection, transferring 10 PB of data would take an extremely long time due to bandwidth limitations. For example, even a 1 Gbps dedicated connection would take over 3 years to transfer 10 PB of data. The time required to transfer such a vast amount of data over the internet is impractical.

• Store the data on an external device and transport it via airship: Correct

Physically transporting large volumes of data using external storage devices can often be much faster than transferring the data over the internet, especially for extremely large datasets like 10 PB. This method avoids the potential bottlenecks and limitations of internet bandwidth and can provide a predictable and secure way to move massive amounts of data.

• Transfer the compressed data files via FTP on the internet: Incorrect

While compression can reduce the amount of data, the time required to transfer 10 PB of even compressed data over the internet is still significant. FTP is not optimized for very large data transfers and can be unreliable over long distances. The transfer speed would still be limited by the internet bandwidth.

• Transfer the encrypted and compressed data via the VPN connection: Incorrect

A VPN connection adds a layer of encryption overhead, which can slow down the transfer speed. Even with compression, the time to transfer 10 PB of data over a VPN would be extensive and impractical due to bandwidth limitations and the added encryption processing time.

Q9: To support seven virtual machines, which subnet provides a minimum number of usable IP addresses?

1. /28
2. /30
3. /27
4. /29

Correct Option: 1

Reason for each option:

• /28: Correct 

/28 provides 16 IP addresses in total, with 14 usable IP addresses after accounting for the network and broadcast addresses.

This is the smallest subnet that provides enough usable IP addresses (14) to support the requirement of 7 virtual machines.

The other options either provide too few usable IP addresses (/30 and /29) or more than necessary (/27), making /28 the most efficient choice in terms of minimizing the number of unused IP addresses while still meeting the requirement.

• /30: Incorrect

Provides only 2 usable IP addresses, which is insufficient to support 7 virtual machines.

• /27: Incorrect

Provides 30 usable IP addresses, which is more than necessary. While it meets the requirement, it does not minimize the number of unused IP addresses as efficiently as /28.

• Provides only 6 usable IP addresses, which is insufficient to support 7 virtual machines: Incorrect

Therefore, /28 is the correct option because it provides the minimum number of usable IP addresses needed to support seven virtual machines.

Q10: Which replication method would you use for only file changes instead of entire file changes?

1. Active Replication.
2. Block-based Replication.
3. Passive Replication.
4. File-based Replication.
   

Correct Option: 2

Read More at Database Replication

Reason for each option: 

• Active Replication: Incorrect

Active replication typically involves keeping multiple copies of data across different locations actively synchronized. It focuses more on redundancy and fault tolerance than efficient data transfer. It does not specifically address replicating only the changes within files.

• Block-based Replication: Correct

Block-based replication tracks and replicates changes at the block level within files. This means that only the modified portions (blocks) of a file are replicated, rather than the entire file. This method is efficient and reduces the amount of data that needs to be transferred, which can save time and bandwidth.

• Passive Replication: Incorrect

Passive replication, also known as primary backup replication, involves a primary server handling all requests and updates, while a backup server remains passive until it is needed. It does not specifically optimize for replicating only changes within files; rather, it ensures that the backup server can take over in case of a failure.

• File-based Replication: Incorrect

File-based replication involves replicating entire files whenever changes are detected. This method is less efficient compared to block-based replication because it transfers the whole file, even if only a small part of it has changed.

Conclusion

In this blog, we’ve covered essential AWS interview questions and answers to help you prepare for your interviews. By studying and practicing these questions, you can enhance your knowledge and confidence, improving your chances of landing your desired AWS role. Whether you’re an experienced professional or new to AWS, this guide will be valuable in your interview preparation. Remember, preparation is the key to success. We hope you find this blog helpful, and we wish you the best of luck in your AWS career!

Frequently Asked Questions

Related/References

• AWS Cloud Job Oriented Program: Step-by-Step Hands-on Labs & Projects
• AWS Exploration: Amazon Web Services
• AWS Certification Path: Learn AWS Certification Hierarchy 2024
• Overview of Amazon Web Services & Concept
• AWS Management Console Walkthrough
• How to create a free tier account in AWS

Next Task For You

Begin your journey towards becoming an AWS Cloud Expert by joining our FREE Informative Class on How to Get High-Paying Jobs in AWS CLOUD Even as a Beginner with No Experience/Coding Knowledge by clicking on the below image.