AWS Solutions Architect and DevOps Job Interview Questions

8 min readJun 24, 2021

The purpose of this questions are to measure your knowledge and identify where to revisit AWS services in order to make sure whether you are ready for the interview

The interview questions cover the following topics

Design for Organisational Complexity
Design for New Solutions
Migration Planning
Cost Control
Continuous Improvement for Existing Solutions

I have prepared the questions with my AWS industry knowledge as well as AWS Solutions Architect — Professional Exam preparation experience. You will see complex questions and very similar answers. The aim of this interview questions to speed up your reading rate and remind the important subjects for the interview. Even if you good at AWS with details, solving lots of questions before the interview is the key point.

You will see the course link at the end of the page

Question 1

The accounting firm has an on-prem database in the Oracle server. Basically, the database is used to store customer information and accounting movements. Due to audit rules, user information needs to be stored for 5 years. Once the audit authority comes in 5 years, they want to query via SQL within random customers in order to see whether customers are being tracked. Due to some financial issues, the accounting firm is supposed to be closed but the historical data (customer list) should be stored in somewhere and needs to be queried within 5 years in case audit wants to check. Accounting firm doesn’t want to pay for the on-prem system as well as Oracle license and they want to keep user information in the cloud and query via SQL when audit needs to check. You have assigned as a solution architect to find the cheapest option for the requirement. Which of the below solution meets for this requirement?

Answers

Export customer information to S3 as a CSV
Create Data Catalog via AWS Glue
Use Athena in order to query customer via SQL

Insert customer information to DynamoDB
Use DynamoDB query component to query customer

Migrate on-prem Oracle database to AWS EC2 server
Use Oracle SQL Developer to query customer

Migrate on-prem Oracle database to Amazon RDS for Oracle
Use Amazon RDS Query Editor to query customer

Answer of Question 1

The following answer is correct

Export customer information to S3 as a CSV
Create Data Catalog via AWS Glue
Use Athena in order to query customer via SQL

All the options can be feasible to get ready for the audit process. Two important points need to be considered

There won’t be any insert, update, delete operation required due to company closure
Data is static no need to put more money for the database license
The only requirement is infrequent query operation

Based on the inputs, the best solution would be to move data to S3 and query via Athena. Other options are more expensive and needs more effort.

Question 2

You are working as a software engineer in a new start-up company. Your company is going to deploy its first mobile gaming app to the AWS platform. The company has a deal with gaming advertisement company to bring approximately 1000 unique user in the first deployment. Your manager informed you that there was a denial of service attacks that happened last week and targeted well-known mobile applications in your region. The attacks consist of a flood of DNS lookups from millions of IP address, then lots of mobile applications were unavailable. Hence you need to consider this situation and find out the approach to prevent DDoS attacks.

What would be the possible solution to tackle this situation?

Answers

Route 53

AWS Shield Advanced

AWS Shield

AWS WAF

Answer of Question 2

AWS Shield is a new managed service that protects your web applications against DDoS (Distributed Denial of Service) attacks. It is also preventing SYN/ACK floods, Reflection attacks, and HTTP slow reads.

If you need more advanced requirement like 7/24 support, real-time reports, intelligent attack detection etc.. you would need AWS Shield advanced. But in the question , there was no mention about these requirements

Wrong answers

Route 53 — Amazon Route 53 is a highly available and scalable cloud Domain Name System (DNS) service instead of preventing DDOS

AWS Shield Advanced — AWS Shield Advanced provides additional detection and mitigation, but there is no need since AWS Shield solve the requirement

AWS WAF — AWS WAF minimise the DDOS attacks, but attacks like SYN floods can be prevent by AWS Shield.

Question 3

The multinational banking company is going to announce a digital board game for its consumer. Every consumer is going to select a Super Mario characters in the digital map. The digital map has multiple stopping points also every stopping point bring the digital coin to the consumer. Once the consumer makes any mobile banking process, the consumer is going to throw the dice and regards to dice number, the consumer move to different places on the map and earn some gaming coins. You have asked to compare database options in AWS to meet with the digital game requirement. The database is supposed to store all related information for the digital game such as consumer information, movements, config definitions and map details.

What would be the proper database approach to meet with this requirement?

Answers

Aurora

RDS

Elasticsearch service

DynamoDB

Answer of Question 3

You have to select NoSQL database to store varied data models in the gaming applications. In this case , the best option is to choose DynamoDB, also best performance for search

Wrong answers

Elasticsearch is also another NoSQL option but it usually used as a search tool and not good for massive amount of data

RDS is relational database option which is not good fit for that requirement

Aurora is performance based relational database option which is not good fit for that requirement

Question 4

A global real estate company collects multiple photos from its clients in order to put a company’s internal system. In the first go-live, the real estate company provided AWS S3 buckets to the clients. The S3 cost is being paid by the real estate company. After sometime later, the client number and uploaded photo volumes are growing significantly, the real estate company decided to create a payment plan to avoid AWS S3 cost. In that case what would be the easiest solution to meet with the requirement?

Answers

Enable Requester Pays for an S3 bucket feature

Implement a Lambda function that is triggered via S3 put event to check the sender and size of the file. Thus, retail company can send a bill to the clients

Implement and schedule a daily  EMR job to check the sender and size of the file

Create a bucket per client and tag them accordingly. Use monthly cost report and send to the clients

Answer of Question 4

All the solutions can be an option but the easiest one is to use S3 Requester Pays feature

In general, bucket owners pay for all Amazon S3 storage and data transfer costs that are associated with their bucket. However, you can configure a bucket to be a Requester Pays bucket. With Requester Pays buckets, the requester instead of the bucket owner pays the cost of the request and the data download from the bucket. The bucket owner always pays the cost of storing data.

https://docs.aws.amazon.com/AmazonS3/latest/dev/configure-requester-pays-console.html

Wrong answers :

Implement a Lambda function that is triggered via S3 put event to check the sender and size of the file. Thus, retail company can send a bill to the clients

The option is a complex solution to meet with the requirement

Implement and schedule a daily  EMR job to check the sender and size of the file

The option is a complex solution to meet with the requirement

Create a bucket per client and tag them accordingly. Use monthly cost report and send to the clients

The option is a complex solution to meet with the requirement

Question 5

An online payment startup is going to deploy its system to the production environment. In the staging environment, they have below services;

Amazon RDS as a database management system
EC2 used as a web application server as well as an application server
S3 is used for backup and to store invoice templates

Since the startup is working on payment domain, the system is supposed to work with high availability. If any interruption happens in the production environment, it will impact the company incomes and customers might get rid of the company. To prepare a stable and high available system, what would be the steps you need to follow?

Answers

Provision a Multi-AZ DB Instance
Provision EC2 instances at least two availability zones
Launch Elastic Load Balancer in front of the EC2
Enable cross-region replication for S3

Provision a Master DB Instance and 2 Read Replicas
Provision EC2 instances at least two availability zones
Launch Elastic Load Balancer in front of the EC2
Enable cross-region replication for S3

Provision a Multi-AZ DB Instance
Provision EC2 instances at least two availability zones
For load balancer, launch Nginx Plus in front of the EC2
Enable cross-region replication for S3

Retransform RDS to DynamoDB to have better availability
Provision EC2 instances at least two availability zones
Launch Elastic Load Balancer in front of the EC2
Enable cross-region replication for S3

Answer of Question 5

The following answer is correct

Provision a Multi-AZ DB Instance
Provision EC2 instances at least two availability zones
Launch Elastic Load Balancer in front of the EC2
Enable cross-region replication for S3

In order to have better availability, you need to launch services in the multiple availability zones. See in the below picture, the load balancer is targeting the requests based on availability. If any issue happens in the one of availability zones, load balancer will direct to running instance set.

Ref : https://aws.amazon.com/blogs/startups/high-availability-for-mere-mortals/

Wrong answers

The following answer is wrong. Read replica doesn’t provide high availability for insert/update operations

Provision a Master DB Instance and 2 Read Replicas
Provision EC2 instances at least two availability zones
Launch Elastic Load Balancer in front of the EC2
Enable cross-region replication for S3

The following answer is wrong.For load balancing, you have Elastic Load balancer service in AWS, no need to install and manage Nginx Plus

Provision a Multi-AZ DB Instance
Provision EC2 instances at least two availability zones
For load balancer, launch Nginx Plus in front of the EC2
Enable cross-region replication for S3

The following answer is wrong. There is no need to transform to DynamoDB. You can also provide high-availability with RDS

Retransform RDS to DynamoDB to have better availability 
Provision EC2 instances at least two availability zones
Launch Elastic Load Balancer in front of the EC2
Enable cross-region replication for S3