AWS Lambda Interview Questions

Basic AWS Lambda Interview Questions

1. What is AWS Lambda?

Amazon Web Services Lambda is an event-driven, serverless computing platform provided by Amazon. As a result, you don't have to worry about which AWS resources to launch or how to manage them. Instead, put the code on Lambda, and it will run.

In AWS Lambda, code is executed in response to events in AWS services such as adding/deleting files in S3 buckets, HTTP requests from Amazon API gateway, and so on. On the other hand, Amazon Lambda can only be used to run background tasks.

AWS Lambda allows you to concentrate on your core product and business logic rather than managing operating system (OS) access control, patching, right-sizing, provisioning, scaling, and so on.
 

2. Which languages does AWS Lambda support?

AWS Lambda supports the following programming languages: Java, Go, PowerShell, Node.js, C#, Python, and Ruby.
 

3. What is AMI?

The term "AMI" refers to an Amazon Machine Image, which is used to supply the necessary data to begin an instance.
 

4. What are some of AWS Lambda's limitations?

The following are a few AWS Lambda restrictions:

• Disc space is restricted to 512 MB.
• The deployment package size is 50 MB by default.
• There are 128 to 3008 MB of RAM available.
• The maximum execution timeout for a function is 15 minutes.

 

5. What do aws lambda path arguments mean?

In the AWS interface, query string arguments are tested using the AWS lambda path parameter.
 

6. What is Hybrid Cloud, exactly?

For communication between each unique service, a hybrid cloud is a service that links a private cloud with one or more public cloud services.
 

7. Describe the SQS dead-letter queue.

Source queues may direct messages that cannot be effectively processed to an SQS dead letter queue.
 

8. How does Elastic Beanstalk work?

Java-developed web applications and services may be easily deployed and scaled using Elastic Beanstalk, an AWS service.
 

9. What does AWS Lambda do?

An AWS Lambda application comprises several resources, including event sources, Lambda functions, and other resources.

10. What are the 3 components of AWS Lambda?

AWS Lambda consists of the following three main components:

1. Event Sources
2. Lambda Functions
3. Compute and Execution Environment

11. What is the Lambda function for AWS?

An AWS Lambda function is a serverless computing service provided by Amazon Web Services (AWS). It allows developers to run code without the need to manage servers. With AWS Lambda, you can upload your code, specify the event sources that trigger the function's execution, and AWS automatically takes care of the rest.
   

12. What are the types of Lambda?

There are no specific types of AWS Lambda in the context of different versions or editions. AWS Lambda is a serverless compute service offered by Amazon Web Services, and it remains consistent across its usage.
 

13. What is a Lambda symbol?

The lambda symbol (λ) is a character from the Greek alphabet. It is commonly used in various fields, like in mathematics, physics, and computer science to represent different concepts.
 

Intermediate AWS Lambda Interview Questions

14. What does AWS Lambda's auto-scaling mean?

An AWS Auto Scaling tool aids in target tracking scaling policies by automatically adjusting supplied concurrency levels.
 

15. What is Serverless Architecture, exactly?

AWS manages all of the servers in a serverless architecture, which eliminates the requirement for infrastructure management when developing or running any application.
 

16. What aspects determine how AWS Lambda is billed?

You are charged according to how long it takes for your code to run, which depends on how many people are using your functions at once and for how long. Every time Lambda starts working in response to an event notification or invoke call, including test invokes via the console, a request is counted.
 

17. To what extent AWS Lambda functions are accessible?

The application was developed to take advantage of redundancy and replication, and as a result, it offers high availability for both Lambda and Amazon services. Additionally, it keeps windows up to date and plans downtime for Amazon Lambda operations.
 

18. Is there a default limit that will be enforced on a functional level?

In AWS Lambda, the default limit only applies at the account level. In essence, the functional level does not apply any preset limits.
 

19. What is meant by an elastic blockage in AWS Lambda?

Users can start working on networking-related tasks in what is effectively a virtual storage area. The user doesn't have to worry about data loss even if a disc in the RAID is broken because this storage readily tolerates faults. Allocating and supplying memory storage are also supported.
 

20. Is vertical scaling possible in Lambda?

Yes, Lambda allows for vertical scaling. One of the most popular features of AWS Lambda is vertical scaling. When a user needs to spin up a more significant instance, they typically use this capability. If they already have an instance running, they can pause and disconnect it from the server. It is crucial to take note of the ID of the new device post to continue the process.
 

21. What steps are involved in creating an AMI?

You must obtain an instance from another reliable AMI before establishing an AMI. The next step is to add both packages and components. If the data is sensitive, you can choose not to add it for security reasons. Add the access credentials as the following step, after which you can register with a database. Depending on the precise needs, the total amount of data you need and have already stored can be increased to any level.
 

22. What precisely is a runtime interface emulator?

Customers can locally test a Lambda function packaged as a container image using the Runtime Interface Emulator. Lambda's Runtime and Extensions APIs serve as a proxy.

 

23. How to use AWS Lambda for ETL?

To use AWS Lambda for ETL follow these points:

• Data Extraction: You need to locate where your data is stored, whether it's in a file storage system or a database. Once you know the location, set up AWS Lambda to actively monitor for any new data that arrives.
• Data Transformation: Write a small piece of code (Lambda function) to clean, organize, and change the data as needed.
• Scaling: AWS Lambda can handle multiple tasks simultaneously, so you don't need to worry about big workloads.
• Security: Ensure that you set up permissions thoughtfully, enabling AWS Lambda to securely access the data and store the results in a protected manner.
• Data Loading: Decide on the destination for the transformed data, such as another storage system, and ensure that the Lambda function properly stores the transformed data at that location.
• Error Handling: Ensure your code is prepared for any potential issues or errors during data processing.
• Monitoring: Use AWS CloudWatch to monitor your Lambda functions and track any problems.

 

24. Does AWS Lambda use load balancer?

No, AWS Lambda does not use a load balancer that works differently from traditional servers, like Amazon EC2 (Elastic Compute Cloud). When you run a Lambda function, AWS automatically handles the server part for you, so you can focus on writing your code and not worry about balancing the work.
 

25. What are the procedures for entering EC2?

To enter an EC2, you can follow these steps:

1. Create EC2 Instance: You set up your virtual server as an EC2 instance on AWS.
2. SSH Key: While setting up your EC2 instance, you select a unique key that is a secure password for connecting to your instance. This helps to ensure a safe and encrypted connection.
3. Connect to EC2: After the instance has been prepared, you utilize your key to establish a connection with it, knocking on the virtual door of your server.
4. Get Public IP or DNS: You discover the address of your EC2 instance, which is analogous to knowing your virtual server's location.
5. Use SSH Command: By employing a specific command on your computer, you connect to the EC2 instance using the chosen address and key.

Advanced AWS Lambda Interview Questions

26. What is an exterior extension?

An extension is considered external if it continues to operate independently even after the function's call has been appropriately handled.
 

27. What does Lambda AVX2 vectorization mean?

The vectorization extension known as AVX2 is utilized to create Lambda workloads or convert current AVX2-enabled workloads to Lambda at no additional cost.
 

28. How may a serverless application be launched?

To begin, users must download the blueprint and console the AWS Lambda. The original file, which should contain both an AWS Sam file and a ZIP file, will then be downloaded. Codes for serverless applications are packaged, deployed, and documented using the AWS Cloud creation commands.
 

29. Outline the benefits of a server-less strategy.

Using a server-less strategy has several significant benefits, including:

• This strategy's straightforward procedures enable speedy time to market and improved sales.
• Users only need to pay for the code when it is compiling, and by increasing the revenues, many costs are reduced.
• The more extensive application's components can be managed easily, and additional infrastructure is available.
   

30. What kind of storage does Amazon offer?

Amazon offers a variety of storage choices that are efficient in both aspects of performance and durability. While solo access can also be supplied depending on the needs, combined access to the storage facility works fine.

• Amazon S3: Amazon S3 is an abbreviation for Simple Storage Service, which offers scalable object storage for data backup, collection, and analytics. Data and files are typically stored in S3 objects, which can be up to 5 GB in size.
• Amazon Elastic File System (EFS):  When using EC2 instances, EFS provides block-level storage volumes for persistent data storage. Amazon EFS provides cloud-based file storage that is managed.
• Amazon Snowball: Snowball is used by businesses to migrate data to the cloud via storage transport devices. Amazon Snowball makes use of AWS Storage Gateway to provide on-premise apps with access to cloud data.
   

31. Do you believe that instances and AMI are related?

They do have a connection to one another. A virtual computer with a defined set of characteristics and an OS can be created as an instance. A complete backup of an instance is an AMI or Amazon Machine Image.
 

32. What are Lambda's security best practices?

One of Lambda's most popular security techniques is using AWS IAM (Identity Access and Management). Another helpful strategy to increase security is to grant specified users access to specific responsibilities. Access might be restricted to hosts that are not trusted or authorized under this security technique. In addition, security protocols should constantly be updated, regardless of how strong and effective they are.
 

33. What is Virtual Private Network?

A secure network connection can be established by using a virtual private network or VPN when accessing public networks.
 

34. What distinguishes the Lambda function from an anonymous class?

The use of keywords differs significantly between a Lambda function and an anonymous class. The keywords in anonymous classes are used to resolve anonymous functional classes, whereas the keywords in Lambda functions are used to resolve functional classes.
 

35. Why do you believe Lambda is a time-saving strategy?

There may be several causes for this. One of these is that Lambda keeps everything in the server's local memory. Another explanation could be that data is directly stored in the database without impacting performance. In addition to these characteristics, Lambda also offers straightforward testing methods. For instance, integration testing can be strengthened by using many suppliers.

Practical AWS Lambda Interview Questions

36. What are the steps to create an Amazon Machine Image (AMI)?

To create an AMI, start by launching an instance from a base, trusted AMI. Next, install and configure the necessary components and packages. For security reasons, avoid including sensitive data. After setting up the instance, add access credentials and configure it with a database if needed. You can scale the stored data according to your specific requirements.

37. What is the AWS Lambda "cold start" problem?

The "cold start" problem occurs when a Lambda function is invoked after being idle for some time, causing a delay as the function’s environment needs to be initialized. Cold starts can impact performance, particularly for functions with heavy initialization.

38. How do we begin working with a serverless application?

To start with a serverless application, you need to connect to AWS Lambda and download the application blueprint. This blueprint typically includes an AWS SAM (Serverless Application Model) template and a ZIP file containing your application code. You can use AWS CloudFormation commands to package, deploy, and manage your serverless application, as well as to generate documentation.

39. What is the role of IAM in AWS Lambda?

IAM (Identity and Access Management) roles are crucial for AWS Lambda as they grant the function the necessary permissions to access other AWS services and resources. The execution role associated with a Lambda function specifies the permissions required for it to operate.

40. What types of tasks can AWS Lambda handle?

AWS Lambda can handle a wide range of tasks. For instance, it can be used to create mobile backends that interact with Amazon DynamoDB for data retrieval and transformation. It can also process and compress objects uploaded to Amazon S3. Additionally, AWS Lambda can manage serverless processing of streaming data via Amazon Kinesis. It supports reporting and auditing API calls for various Amazon web services, among many other activities.

41. How can you monitor AWS Lambda function performance?

You can monitor Lambda function performance using:

• AWS CloudWatch Logs: For logging function output and errors.
• AWS CloudWatch Metrics: For monitoring function invocations, duration, errors, and other performance metrics.
• AWS X-Ray: For tracing and analyzing function performance and identifying bottlenecks.

42. What are the drawbacks of using a serverless approach?

While AWS Lambda offers many benefits, it also has its drawbacks. One major limitation is the reliance on the vendor, which can result in increased downtime. Additionally, the lack of dedicated hardware can lead to reduced system functionality and other constraints. Serverless environments can sometimes encounter issues due to system limits or customer errors, affecting overall performance and reliability.

43. What are the benefits of using AWS Lambda with Step Functions?

AWS Lambda combined with AWS Step Functions allows you to build complex workflows with multiple Lambda functions. Step Functions provide orchestration, error handling, and retry mechanisms, making it easier to manage complex processing logic.

44. What are the best practices for writing efficient AWS Lambda functions?

To write efficient AWS Lambda functions, follow these tips:

• Optimize your code to run faster and use fewer resources.
• Use environment variables to manage settings and configuration.
• Use asynchronous invocations for tasks that take a long time to complete.
• Implement caching to avoid repeating the same processing tasks.

45. How can you manage secrets in AWS Lambda?

You can manage secrets in AWS Lambda by:

• AWS Secrets Manager: To securely store and manage sensitive information.
• AWS Systems Manager Parameter Store: For storing configuration data and secrets with encryption.
• Environment Variables: To store sensitive data, though this is less secure than the other methods.

46. What is the pricing model for AWS Lambda?

AWS Lambda pricing includes:

• Number of requests: Charged per million requests.
• Duration: Charged based on how much memory you use and how long your function runs.
• Provisioned Concurrency: Charged for keeping a set number of function instances ready to go.

47. What is the difference between AWS Lambda and AWS Fargate?

AWS Lambda is for running short-lived, event-driven functions without managing servers. AWS Fargate is for running containerized applications and services that require longer runtime and more complex setups.

48. Can you use AWS Lambda for batch processing tasks?

Yes, AWS Lambda can handle batch processing by working with services like SQS or Kinesis. It can process messages from SQS queues or records from Kinesis streams in parallel.

49. What is AWS Lambda provisioned concurrency?

Provisioned concurrency is a feature that keeps a set number of Lambda function instances warm and ready, reducing delays from cold starts and ensuring faster response times.

50. How do you implement error handling in AWS Lambda functions?

Error handling in AWS Lambda can be implemented using:

• Try-catch blocks: To catch and handle exceptions within your code.
• Retries: Automatic retries for transient errors.
• Dead Letter Queues (DLQs): To capture failed events for later inspection and handling.
• Custom error handling logic: To implement specific actions based on different error types.

Conclusion

In this article, we have extensively discussed the AWS Lambda Interview Questions and answer series covering the various-level AWS Lambda Interview Questions.

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