AWS Data Engineer Interview Questions

Hi there, welcome back to my another blog!

In our previous blog, we discussed 20 AWS Data Engineer interview questions. Today, in this blog, we are going to explore the top 20 more AWS Data Engineer interview questions, so that you can answer each of them confidently without any hesitation.  I have framed the answers to all these questions based on my experience. You can get the idea from this blog and you can reframe the answer in your own way. My motive behind writing this blog is simply to share ideas and help you prepare better for interviews.

What is Amazon S3?

Amazon S3 is an object storage service built to retrieve any amount of data from anywhere.

S3 is frequently used in data engineering as a scalable and durable storage solution for storing raw or processed data. It allows you to data lakes and store backups because of its connection with other AWS services.

What are the benefits of Amazon S3?

• It is scalable; you can store any amount of data virtually with S3.
• Amazon S3 offers industry-leading availability and the cloud’s most robust storage.
• S3 is designed to deliver 99.99% availability and 99.999999999 data durability by default.
• S3 offers a wide range of auditing features to keep an eye on requests for access to your S3 resources.
• You can store enormous volumes of frequently, infrequently, or rarely accessed data in  a cost-efficient way because S3 delivers multiple storage classes.

What is AWS Lambda?

AWS Lambda is a serverless compute service that allows you to run code using AWS Lambda without managing a physical server.

AWS Lambda is used in data engineering to manage event-driven processing, automate processes and interface with other AWS services to create scalable and effective pipelines.

What is AWS Glue Studio?

AWS Glue Studio is a visual tool included in the AWS Glue service. With the use of a drag-and-drop feature, you can easily build, execute, and track ETL operations without writing a lot of code. It is especially designed for those who prefer visual design over code.

• It makes data integration easier for data analysts and data engineers.
• You can build complete ETL jobs without needing to write Spark or  Scala scripts manually.
• It automatically generates Spark code in the background for the job, which you view and edit.
• It connects easily to  Amazon S3, Redshift, RDS, DynamoDB and other AWS data sources.

What is Bucket?

An Amazon S3 bucket is a public cloud storage resource in Amazon S3. In S3 buckets, data is stored in object form instead of files. Amazon S3 buckets are similar to file folders and can be used to store, retrieve, back up and access objects. An Amazon S3 bucket allows to store infinite amount of data for a variety of use cases.

What is CDC?

CDC stands for  Change Data  Capture. It is a data integration pattern used to identify and capture data changes(inserts, deletes, updates). CDC can be implemented by using various tools and methods like Amazon Kinesis with AWS Lambda, DMS, Amazon Aurora with AWS Lambda and Amazon MSK(Kafka).

What are the Storage Classes available in Amazon S3?

Amazon S3 offers different classes :

• S3 Standard
• S3 Intelligent-Tiering
• S3 Standard-IA
• S3 One Zone-IA
• S3 Glacier
• S3 Glacier Deep Archive

What is OLTP?

OLTP stands for Online Transaction Processing. It is used to manage transaction -oriented tasks, including adding, updating, or deleting records related to transactions in real time.

For example, when you place an order on any e-commerce website, the system instantly records your order details with the help of OLTP. Amazon RDS and DynamoDB are suitable for OLTP systems.

Explain the working of  Amazon Kinesis.

Amazon Kinesis is a service provided by Amazon Web Services allow to manage large amount of data including audio, videos etc. It can handle the real-time large streams of data. It allows users to collect, store, capture, and process many logs from distributed streams such as social media feeds.

The working of Amazon Kinesis is divided into four stages.

• Data Ingestion
• Sharding and Scaling
• Processing and Buffering
• Making the data scalable

Data Ingestion: Amazon Kinesis first collects the data from the different sources, and the format of the data can be in JSON or Binary format.

Sharding and Scaling: Data which is received from different sources is divided into small parts called shards for redundancy and fault tolerance.

Processing and Buffering: After sharding the data, it applies the filter before storing the data.

Making the data scalable: It offers various ways to access and utilize your data stream, including Kinesis Data Streams API, Kinesis Firehose, and Kinesis Analytics.

What is DynamoDB Accelerator (DAX) in Data Engineering?

DynamoDB Accelerator(DAX) is an in-memory caching service for Amazon DynamoDB, a fully managed NoSQL database service. DAX stores frequently used data in memory and lies between your application and DynamoDB. You can utilize DAX without changing your application code because it works with the DynamoDB API calls that are already in place. Integration of DAX with existing DynamoDB is simple.

What is OLAP?

OLAP stands for Online Analytical Processing. It is used for analyzing large volumes of data. It runs complex queries and generates report based on historical data. Organizations use this to understand their sales trends and to compare performance.

What is SnowBall?

Amazon Web Service provides the data migration and edge computing device called SnowBall. It is designed to securely transfer large amounts of data inside and outside of the AWS environment.

We follow some steps to work with Snowball:

• First, send an AWS console request for a Snowball with the necessary capacity.
• Once you send request, Snowball is shipped to your location via AWS.
• Connect the Snowball to your local network.
• Use the Snowball client or AWS OpsHub to copy data to the device.
• Ship it back to AWS using the pre-labelled return.
• Lastly, AWS uploads the data to your specified S3 bucket.

What is AWS Elastic Transcoder?

AWS Elastic Transcoder is a media transcoding service provided by AWS. It allows you to convert one file format to another so that they can be played on different devices.

For example, if you upload a high-quality video in one format, but your audience is using different devices like smartphones, tablets, and laptops to access. But they cannot access it on multiple devices because you uploaded it in one format, and to solve this problem, Elastic Transcoder helps to convert your media into different formats that are optimized for each device or platform, so that users can easily access it.

What are the different types of cloud computing?

There are different types of cloud services, including:

• Software as a Service(SaaS)
• Data as a Service(DaaS)
• Platform as a Service(PaaS)
• Infrastructure as a Service(IaaS)

What is the Difference between IaaS, PaaS, and SaaS?

What is Geo-Targeting in CloudFront?

Geo-Targeting enables the creation of customized content based on the geographic location of the user. It helps you show more relevant content depending on the user’s location.

For example, there is one person who wants to see news about market trends, while another person from the  US wants to see updates about football tournaments. And all this is possible with the help of Geo-Targeting.

What are the different types of Instances?

There are different types of instances, some of them are:

• Compute Optimized
• Memory Optimized
• Storage Optimized
• Accelerated Computing
• General Purpose

What is a Security Group?

A Security Group in AWS acts like a virtual firewall for your instances. It controls the access of instance. Based on port numbers, IP addresses or protocols, you can set rules to block traffic.

What is Amazon Athena?

Amazon Athena allows you to use SQl queries to search and analyze your data in S3. It is a serverless tool in AWS. You can directly perform SQL queries on data without needing to set up any servers or databases.

What is the  difference between Star schema and Snowflake schema?