20 AWS IoT Interview Questions and Answers

AWS IoT is a cloud platform that enables developers to connect and manage devices in the cloud. It is a popular choice for developers who are looking to build IoT applications. During a job interview, you may be asked questions about your experience with AWS IoT. Knowing how to answer these questions can help you impress the hiring manager and improve your chances of getting the job. In this article, we discuss the most commonly asked AWS IoT interview questions and how you should respond.

AWS IoT Interview Questions and Answers

Here are 20 commonly asked AWS IoT interview questions and answers to prepare you for your interview:

1. What is AWS IoT?

AWS IoT is a platform that enables you to connect devices to the AWS cloud and to other devices. With AWS IoT, you can create applications that manage and process data from devices in the AWS cloud, or build applications that interact with devices in the AWS cloud.

2. What are the main components of AWS IoT?

The main components of AWS IoT are the Device Gateway, the Message Broker, and the Rules Engine. The Device Gateway allows devices to connect to the AWS IoT platform, the Message Broker allows for communication between devices and the AWS IoT platform, and the Rules Engine allows for the execution of rules and actions based on data from devices.

3. Can you explain what an AWS IoT device shadow is? How do they work?

A device shadow is a virtual representation of an IoT device that includes the device’s current state, desired state, and timestamp. Device shadows are used to store and retrieve information about an IoT device, and they can be used to synchronize the state of multiple devices.

4. What types of messages can be sent using AWS IoT Core?

AWS IoT Core supports two types of messages:

1. Device-to-cloud messages are sent from devices to AWS IoT and can be up to 256 KB in size.

2. Cloud-to-device messages are sent from AWS IoT to devices and can be up to 64 KB in size.

5. What’s the difference between a thing and a certificate in AWS IoT?

A thing is a representation of a physical device in AWS IoT. A certificate is used to authenticate a device when it connects to AWS IoT.

6. How does AWS IoT handle security for devices that connect to it?

AWS IoT uses a number of security measures to protect devices that connect to it. These include using SSL/TLS to encrypt communication, using mutual authentication to ensure that only authorized devices can connect, and using policies to control what devices can do.

7. What are some common use cases for AWS IoT?

Some common use cases for AWS IoT include connecting and managing devices in the Internet of Things, building applications that collect and analyze data from devices, and creating applications that enable devices to interact with each other.

8. What is a topic in AWS IoT?

A topic is a communication channel through which devices can publish and subscribe to messages.

9. What types of data storage options are available when working with AWS IoT?

AWS IoT provides a few different storage options for data, including Amazon DynamoDB, Amazon Simple Storage Service (S3), and Amazon Kinesis Streams.

10. How many certificates can a single device have?

A single device can have up to four certificates.

11. What are rules and actions in AWS IoT?

Rules and actions are how you set up AWS IoT to automatically respond to events. A rule can be triggered by a specific message, or by a message that meets certain criteria, and then an action is performed. Actions can be to send a message to another AWS service, to invoke a Lambda function, or to store the message in an Amazon S3 bucket.

12. Is it possible to limit access to certain devices or resources on AWS IoT? If yes, then how?

Yes, it is possible to limit access to certain devices or resources on AWS IoT. You can do this by creating an IAM policy that specifies the conditions under which a device or resource can be accessed. For example, you could create a policy that only allows devices with a certain MAC address to access a particular resource.

13. What is the best way to keep track of events occurring on your AWS IoT platform?

The AWS IoT platform provides a number of ways to keep track of events, including the AWS IoT Events service, the AWS IoT Device Management service, and the AWS IoT Device Shadow service. Each of these services provides different capabilities and can be used to track different types of events.

14. What are some of the limitations of AWS IoT?

One of the key limitations of AWS IoT is that it only supports devices that use the MQTT or HTTPS protocols. This can be a limiting factor if you are trying to connect to devices that use other protocols. Additionally, AWS IoT can be expensive to use at scale, as it charges per device and per message.

15. Which other services from the Amazon ecosystem do you integrate with while working with AWS IoT?

AWS IoT can be integrated with a number of other Amazon services, including Amazon DynamoDB, Amazon S3, Amazon Kinesis, and Amazon CloudWatch. This allows you to store and analyze data collected by your IoT devices, as well as to trigger certain actions based on conditions that you set.

16. What is the best practice for managing multiple versions of code running on different devices connected to AWS IoT?

The recommended best practice for managing multiple versions of code running on different devices connected to AWS IoT is to use AWS IoT Greengrass. This allows you to manage and deploy your code to different devices from a single location, and also provides features such as versioning and rollback so that you can easily control which devices are running which version of your code.

17. What is the significance of versioning when working with AWS IoT? Does it help prevent breaking changes or provide backward compatibility in any way?

Versioning is important when working with AWS IoT because it allows you to maintain different versions of your IoT devices and applications. This way, if you need to make a breaking change to your IoT application, you can maintain a previous version that is still compatible with your older devices. Versioning also allows you to gradually roll out new features and functionality to your IoT devices, so that you can test and debug new code before it is deployed to all of your devices.

18. What kind of testing should be done before deploying new code to live devices on AWS IoT?

Before deploying new code to live devices on AWS IoT, it is recommended that you first test the code in a simulated environment. This will allow you to test the code without affecting any real devices. Once you have confirmed that the code works as expected in the simulated environment, you can then deploy it to live devices.

19. How do you ensure that the data transferred over AWS IoT is secure and encrypted?

AWS IoT uses SSL/TLS to encrypt all data in transit. This ensures that all data passing through the AWS IoT platform is secure and encrypted.

20. Where could I find the latest API’s and SDK’s for AWS IoT?

The latest API’s and SDK’s for AWS IoT can be found on the AWS IoT Developer Guide website.