AWS IoT Interview Q/A

What is AWS IoT Core?
AWS IoT Core is a managed cloud service provided by Amazon Web Services (AWS) that allows you to connect IoT (Internet of Things) devices to the cloud. It provides the infrastructure and services for securely connecting and managing IoT devices, processing and storing data from these devices, and enabling communication and actions based on that data.

Can you explain what an AWS IoT device shadow is?
An AWS IoT device shadow is a JSON document that represents the current and desired state of an IoT device. It allows you to synchronize and manage the state of IoT devices even when they are offline. The device shadow contains a "reported" state, which reflects the device's actual state, and a "desired" state, which represents the desired state for the device. Applications can read and update the shadow to control and monitor devices.

What does AWS IoT Core offer?
AWS IoT Core offers a range of features and services for IoT device management, connectivity, and data processing. This includes secure device authentication, MQTT and HTTP communication protocols, device shadows, a rules engine for data processing, integration with various AWS services, and the ability to scale for large numbers of connected devices.

What are the main components of AWS IoT?
The main components of AWS IoT include:

• Device Gateway: It enables communication between devices and the AWS cloud.

• Rules Engine: It processes and routes data from devices to other AWS services.

• Device Shadows: JSON documents representing device states.

• Registry: A collection of "things" representing connected devices.

• Security Features: Including device authentication and access control.

• Integration with AWS Services: Such as S3, DynamoDB, Lambda, and more.

How does AWS IoT Core work?
AWS IoT Core works by allowing IoT devices to connect to the AWS cloud securely, send data to the cloud, and receive commands or updates from applications. It provides a reliable and scalable platform for IoT device management and data processing, enabling real-time monitoring and control of devices.

What types of messages can be sent using AWS IoT Core?
AWS IoT Core supports the publishing and subscribing of messages in JSON format using the MQTT and HTTP protocols. These messages can contain data from IoT devices, updates to device shadows, and commands to control devices.

What's the difference between a thing and a certificate in AWS IoT?
In AWS IoT, a "thing" represents a physical or virtual device connected to the platform, and it is used to manage and track devices. A "certificate" is a digital certificate used for device authentication, enabling secure connections between devices and AWS IoT. A certificate is associated with a thing to allow the thing to connect to the AWS IoT platform securely.

How does AWS IoT handle security for devices that connect to it?
AWS IoT implements security through device authentication using X.509 certificates and access control policies. It also employs Transport Layer Security (TLS) for data in transit, and it provides features for message encryption, network isolation, and auditing to ensure the security of IoT devices and data.

What are some common use cases for AWS IoT?
Common use cases for AWS IoT include asset tracking, industrial monitoring and control, smart home automation, predictive maintenance, remote monitoring of devices and sensors, and building IoT applications in various industries, including healthcare, agriculture, and logistics.

What is a topic in AWS IoT?
In AWS IoT, a "topic" is a communication channel used for the publish-subscribe messaging pattern. Devices can publish messages to topics, and other devices or applications can subscribe to those topics to receive messages. Topics are used to categorize and organize messages, making it easy to route messages to the right recipients.

What are some of the limitations of AWS IoT?
AWS IoT has limitations related to data volume, throughput, device connectivity, device compatibility, security, and cost. These limitations can vary depending on the specific AWS IoT service being used and may require adjustments in application architecture to overcome.

Which other services from the Amazon ecosystem do you integrate with while working with AWS IoT?
AWS IoT integrates with various Amazon services, including Amazon S3, Kinesis, DynamoDB, Redshift, and SageMaker. These integrations allow you to build and scale IoT applications efficiently within the Amazon ecosystem.

What is the best practice for managing multiple versions of code running on different devices connected to AWS IoT?
Best practices for managing multiple code versions on AWS IoT devices include utilizing versioning, thorough code testing, incremental code deployment, and device monitoring. These practices help ensure code reliability and minimize risks during updates.

What is the significance of versioning when working with AWS IoT?
Versioning in AWS IoT helps track code versions on devices, enabling effective management and the ability to roll back to previous versions if needed. It also assists in preventing breaking changes and ensuring backward compatibility.

What kind of testing should be done before deploying new code to live devices on AWS IoT?
Various types of testing, including unit testing, integration testing, performance testing, security testing, and user acceptance testing, should be conducted before deploying new code to live devices on AWS IoT to ensure reliability and functionality.

How do you ensure that the data transferred over AWS IoT is secure and encrypted?
AWS IoT ensures data security and encryption through measures such as TLS for data in transit, X.509 certificates for device authentication, access control policies, message encryption with AWS Key Management Service (KMS), network isolation options, and auditing and monitoring capabilities.

Where could I find the latest APIs and SDKs for AWS IoT?
The latest APIs and SDKs for AWS IoT can be found in the AWS IoT Developer Guide, AWS IoT API Reference, AWS IoT SDKs page, and on AWS's GitHub repository. These resources provide comprehensive documentation, API references, SDK downloads, and up-to-date information for developing IoT applications with AWS IoT.

What is 2lemetry and how does it relate to AWS IoT?
2lemetry was an IoT platform company that Amazon acquired in 2015. Its technology was integrated into AWS IoT, and its expertise contributed to the development of AWS IoT Core and related services.

In which regions is AWS IoT Core available?
AWS IoT Core is available in various AWS regions, including Asia Pacific (Tokyo) and others. You can choose the region closest to your users or devices for optimal performance.

How do I get started with using AWS IoT Core?
To get started with AWS IoT Core, you need to:

• Sign up for an AWS account.

• Set up a device capable of connecting to the Internet.

• Create a "thing" within AWS IoT Core.

• Connect your device to AWS IoT Core.

• Send data to AWS IoT Core.

• Analyze and act on the data using AWS IoT Core features.

Which languages does the AWS IoT Console support?
The AWS IoT Console is available in multiple languages, including English, Japanese, Korean, Simplified Chinese, German, French, Spanish, and Portuguese (Brazil). You can change the language of the console to your preferred language using the language selector.

What are the ways to access AWS IoT Core?
You can access AWS IoT Core through various means, including the AWS Management Console, AWS SDKs, AWS CLI, AWS IoT Core APIs, and AWS IoT Device SDKs, depending on your specific requirements.

What communication and authentication protocols does AWS IoT Core support?
AWS IoT Core supports the MQTT and HTTP communication protocols and uses X.509 certificates for device authentication.

What types of data storage options are available when working with AWS IoT? Data storage options for AWS IoT include Amazon S3, Amazon DynamoDB, Amazon Redshift, and Amazon Elasticsearch Service. These services allow you to store and analyze data generated by IoT devices.

What are the rules and actions in AWS IoT?
Rules and actions in AWS IoT are used to process and route data from devices to other AWS services. Rules are defined with conditions, and actions are taken when those conditions are met. For example, a rule can route data to DynamoDB, or S3, or invoke a Lambda function.

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 specific devices or resources on AWS IoT. This can be achieved through AWS Identity and Access Management (IAM) policies, AWS IoT policies, and network isolation mechanisms. IAM policies and IoT policies allow you to control access to resources, and network isolation ensures that only authorized parties can access devices.

What is the best way to keep track of events occurring on your AWS IoT platform?
To monitor events on your AWS IoT platform, you can use AWS IoT logs, AWS CloudWatch, AWS IoT Events, or create custom monitoring and alerting systems. These methods help you track and respond to events effectively.

Can devices that are NOT directly connected to the Internet access AWS IoT Core?
Devices that are not directly connected to the internet can still access AWS IoT Core through mechanisms like HTTP proxy, AWS Greengrass, or a gateway device that bridges the local network with AWS IoT.

How should applications access AWS IoT Core?
Applications can access AWS IoT Core in two primary ways: companion apps (for end-users) and server applications. Companion apps use identity providers like Amazon Cognito for user access, while server applications use IAM roles for secure and controlled access to AWS IoT Core resources.

Can I get a history of AWS IoT Core API calls made on my account for security analysis and operational troubleshooting purposes?
Yes, you can obtain a history of AWS IoT Core API calls through AWS CloudTrail and AWS IoT logs. CloudTrail records API calls and delivers log files for security analysis, while IoT logs provide details about device connections, data transfers, and rule evaluations for operational troubleshooting.