Magento 2 Interview Questions & Answers: Backend, Frontend, API, Cron Jobs, Security

General Magento 2 Questions – Answers

1. What is Magento 2?

Magento 2 is an open-source e-commerce platform written in PHP. It provides online merchants with a flexible shopping cart system, control over look, content, and functionality of their online store, and powerful tools for marketing, SEO, and catalog management.

2. What are the main features of Magento 2?

  • Modular architecture
  • Improved performance and scalability
  • Mobile-friendly responsive design
  • Built-in caching and indexing
  • Support for latest PHP versions and frameworks
  • Enhanced admin interface

3. What is the difference between Magento 1 and Magento 2?

  • Architecture: Magento 2 uses a modern technology stack (PHP 7+, Composer, Symfony, etc.)
  • Performance: Magento 2 has full-page caching and is much faster than Magento 1.
  • Admin Interface: More user-friendly and responsive in Magento 2.
  • Database: Magento 2 supports split databases for checkout, order, and product.

4. What is the Magento 2 folder structure?

Important directories include:

  • app/: Code, configuration, and themes.
  • pub/: Public web root.
  • vendor/: Third-party Composer packages.
  • generated/: Generated code by Magento (DI, proxies, etc.).

5. How do you enable or disable modules in Magento 2?

php bin/magento module:enable Vendor_Module
php bin/magento module:disable Vendor_Module

6. What are the different types of cache in Magento 2?

  • Configuration
  • Layout
  • Block HTML Output
  • Collections Data
  • Page Cache (FPC)
  • Reflection Data
  • Translation

7. How do you clear cache in Magento 2?

php bin/magento cache:clean
php bin/magento cache:flush

8. What is Dependency Injection (DI) in Magento 2?

Dependency Injection is a design pattern used in Magento 2 to manage object dependencies. Magento injects required classes via constructors rather than creating objects manually, making the code more testable and loosely coupled.

9. What is the use of `di.xml` file in Magento 2?

The di.xml file is used for dependency injection configurations, including preferences (class rewrites), plugins (interceptors), and virtual types.

10. What is a plugin in Magento 2?

A plugin (also known as an interceptor) allows you to modify the behavior of a public method in a class without overriding the class. It supports three types: before, after, and around methods.

11. How do you create a custom module in Magento 2?

Steps:

  1. Create app/code/Vendor/Module/registration.php
  2. Create module.xml under etc/
  3. Register the module with php bin/magento setup:upgrade

12. What is the command to upgrade setup and compile DI in Magento 2?

php bin/magento setup:upgrade
php bin/magento setup:di:compile

13. How does Magento 2 routing work?

Routing in Magento 2 is handled by the front controller. It reads the URL and uses routes.xml to match the request to the appropriate controller/action pair.

14. How do you override a controller in Magento 2?

You can override a controller by creating a preference in di.xml or using plugin/interception methods, but preference should be used carefully to avoid conflicts.

15. What are observers and events in Magento 2?

Magento 2 uses the event-observer pattern. Events are dispatched in code using $this->eventManager->dispatch(). Observers listen for these events and execute custom logic.

16. What is the use of `setup:static-content:deploy`?

This command deploys static files (JS, CSS, images) to the pub/static directory, especially for production environments.

php bin/magento setup:static-content:deploy

17. What is the difference between cache:clean and cache:flush?

  • cache:clean: Cleans only Magento’s cache that it knows about.
  • cache:flush: Flushes the entire cache storage including third-party or custom entries.

18. How do you enable developer mode in Magento 2?

php bin/magento deploy:mode:set developer

19. What is Magento 2 Cron?

Magento uses cron jobs to schedule repetitive tasks like sending emails, generating sitemap, reindexing, and more. Cron configuration is located in crontab.xml.

20. What is the difference between `webapi.xml` and `routes.xml`?

  • webapi.xml: Defines REST/SOAP API endpoints and services.
  • routes.xml: Defines frontend and admin routing paths for controllers.

Magento 2 Backend Development Questions – Answers

1. How do you create a custom module in Magento 2?

Steps:

  1. Create registration.php under app/code/Vendor/Module/
  2. Create module.xml under etc/
  3. Run php bin/magento setup:upgrade

2. What is the purpose of the di.xml file?

di.xml is used for configuring Dependency Injection. It allows you to declare preferences, plugins, virtual types, shared instances, and factories.

3. What is the difference between a preference and a plugin?

  • Preference: Overrides a class entirely.
  • Plugin: Intercepts a method call using before, after, or around logic.

4. How do you create a custom admin route in Magento 2?

Create routes.xml in etc/adminhtml/ and define a controller under Controller/Adminhtml/.

5. How do you add a custom admin menu?

Use menu.xml in etc/adminhtml/ and define your menu item using proper ACL resources and module controller paths.

6. How do you add a custom ACL rule in Magento 2?

Define permissions in acl.xml and use them in menu.xml and your controller with:

$this->_authorization->isAllowed('Vendor_Module::resource_name')

7. How do you create a custom table in Magento 2?

Use a Setup/InstallSchema.php (or Setup/UpgradeSchema.php in newer versions) file in your module to define and install the table schema using $installer->getConnection()->newTable().

8. How do you insert or update data in a custom table?

Use the ResourceModel or direct DB connection:

$connection = $this->resourceConnection->getConnection();
$connection->insert('custom_table', ['field' => 'value']);

9. What is a Repository in Magento 2?

Repository is a part of the service layer. It provides a consistent interface for accessing data objects (CRUD) and enforces service contracts.

10. How do you create a custom model and resource model?

Steps:

  • Create model: Model/Entity.php
  • Create resource model: Model/ResourceModel/Entity.php
  • Link them in _construct() method.

11. What is a collection in Magento 2?

A collection is a class that loads multiple records from the database. It extends \Magento\Framework\Model\ResourceModel\Db\Collection\AbstractCollection.

12. How do you create an admin grid in Magento 2?

Create a UI component XML in view/adminhtml/ui_component/ and define your data source, columns, filters, and buttons.

13. How do you add a mass action in admin grid?

Define a massaction node inside your UI component XML and add controller logic for the mass action class.

14. How do you use events and observers in Magento 2?

Use events.xml to define the observer and implement the logic inside Observer/YourObserver.php. Example:

public function execute(\Magento\Framework\Event\Observer $observer) {
    $event = $observer->getEvent();
}

15. What is the difference between setup:upgrade and setup:db-schema:upgrade?

  • setup:upgrade: Applies schema and data changes and upgrades modules.
  • setup:db-schema:upgrade: Only applies schema changes without touching data.

16. What is a service contract in Magento 2?

Service contracts are interfaces (API) defined in Api/ directory. They are used to expose consistent service layers for modules.

17. How do you implement a custom plugin (interceptor)?

Create a class in Plugin/ folder and configure it in di.xml like this:

<type name="TargetClass">
    <plugin name="custom_plugin" type="Vendor\Module\Plugin\YourPlugin" />
</type>

18. What is the purpose of Factory and Proxy classes?

  • Factory: Used to create new instances of objects.
  • Proxy: Used to delay loading of objects (lazy loading), improving performance.

19. How do you create a custom configuration in the admin?

Create system.xml in etc/adminhtml/ and define configuration sections, groups, and fields.

20. How do you read configuration values?

$this->scopeConfig->getValue('section/group/field', \Magento\Store\Model\ScopeInterface::SCOPE_STORE);

Magento 2 Frontend Development Questions – Answers

1. What is the structure of a Magento 2 theme?

A theme is located under app/design/frontend/Vendor/theme and contains folders like:

  • etc/ – theme.xml
  • web/ – static files (CSS, JS, images)
  • Magento_*/ – module-based template and layout overrides

2. How do you override a template in Magento 2?

Create the path in your theme like app/design/frontend/Vendor/theme/Magento_Module/templates/filename.phtml.

3. What is a layout XML file in Magento 2?

Layout XML defines the structure of pages and is stored in layout/. Common handles: default.xml, catalog_product_view.xml, etc.

4. How do you add a CSS/JS file in Magento 2?

Use default_head_blocks.xml or page-specific layout files with:

<head>
  <css src="css/styles.css"/>
  <script src="js/custom.js"/>
</head>

5. How do you create a custom block in Magento 2?

Create a class extending \Magento\Framework\View\Element\Template and call it from layout XML with a referenceBlock or container.

6. What is a static block (CMS block)?

A CMS block is a reusable HTML block that can be added to pages via admin, layout XML, or widgets.

7. What are ViewModels in Magento 2?

ViewModels are preferred over blocks for business logic. Add in layout.xml using the viewModel attribute.

8. What is the purpose of requirejs-config.js?

To configure JavaScript dependencies, define paths, shims, and mixins. It is used for asynchronous module loading via RequireJS.

9. How do you create a custom LESS file in Magento 2?

Create a file under web/css/source/_extend.less and include it in web/css/styles-l.css or through theme.xml.

10. How do you override a layout in a custom theme?

Copy the layout XML from the module’s view/frontend/layout to your theme’s corresponding folder and modify it.

11. How do you display a custom block on a specific page?

Use layout XML with a specific page handle, e.g., cms_index_index.xml for the homepage.

12. What is the purpose of UI Components in Magento 2 frontend?

UI Components are XML-driven components used for rendering complex elements (e.g., grids, forms) in admin and frontend.

13. What is Knockout.js used for in Magento 2?

Magento uses Knockout for dynamic frontend rendering in modules like checkout and customer account sections.

14. How do you add a widget in Magento 2?

From the admin panel: Content → Widgets → Add Widget → Choose type and assign to a layout.

15. How do you customize the product page layout?

Override catalog_product_view.xml in your theme and modify blocks and containers as needed.

Magento 2 Admin Panel Interview Questions – Answers

1. How do you create a custom menu in the Magento admin panel?

Create a menu.xml file in etc/adminhtml/ and define menu items with title, module, sortOrder, and action.

2. How do you create a custom admin controller?

Create a class under Controller/Adminhtml/YourController.php extending \Magento\Backend\App\Action and define the execute() method.

3. What is ACL and how is it used in the admin panel?

ACL (Access Control List) defines permissions. It’s configured in acl.xml and used in controllers with:

$this->_authorization->isAllowed('Vendor_Module::resource');

4. How do you create a system configuration in the admin panel?

Define it in etc/adminhtml/system.xml with sections, groups, and fields. Values are saved in the core_config_data table.

5. How do you add custom validation to system config fields?

Use the frontend_model attribute and create a block class extending \Magento\Config\Block\System\Config\Form\Field.

6. How do you create a custom admin form?

Use a UI Component form declared in view/adminhtml/ui_component/form.xml. Define dataSource, fields, buttons, and layout.

7. How do you display flash messages (success/error) in admin?

Use the message manager:

$this->messageManager->addSuccessMessage(__('Success!'));
$this->messageManager->addErrorMessage(__('Something went wrong.'));

8. How do you create a mass action in admin grid?

In your UI Component grid XML, define a massaction block and link to a controller that handles the batch processing logic.

9. How do you use dependency injection in admin classes?

Inject classes like Context, PageFactory, Registry, and others via constructor.

10. How do you translate text in admin panel?

Use the __() function, e.g., __('Edit Product'). Translations are managed via CSV files in i18n/.

11. How do you restrict access to a controller in admin?

Use the _isAllowed() method inside your controller and map ACL resources in acl.xml.

12. How do you create adminhtml routes?

Define them in etc/adminhtml/routes.xml with a frontName, id, and module reference.

13. How can you configure cron jobs from admin?

Magento cron jobs are defined in crontab.xml and scheduled via system cron. Some modules allow enabling/disabling cron logic from admin config (system.xml).

14. What is the role of Data Patch in Magento 2 admin configuration?

Data patches are used to insert or modify configuration data (e.g., default admin settings) programmatically using Setup/Patch/Data classes.

15. How do you debug issues in the admin panel?

Check logs in var/log, enable developer mode, use browser dev tools, and inspect UI component XML or ACL settings.

Magento 2 API – Interview Questions and Answers

1. What types of APIs are available in Magento 2?

Magento 2 supports REST, SOAP, and GraphQL APIs for interacting with the system programmatically.

2. How do you create a custom REST API endpoint?

Define a webapi.xml file, create a repository interface, and implement it with service contracts.

3. How do you authenticate Magento 2 APIs?

Using tokens: Customer Token (via /V1/integration/customer/token) or Admin Token (/V1/integration/admin/token).

4. How can you test Magento APIs?

Using tools like Postman, Curl, or browser GraphQL playground (for GraphQL APIs).

5. What is service contract in Magento 2?

It’s a set of PHP interfaces that define the public API. Used for decoupling modules and supporting web services.

6. How do you add custom attributes to an API response?

Use extension attributes via the extension_attributes.xml and add them to your data interface.

Magento 2 Cron Jobs – Interview Questions and Answers

1. Where do you define cron jobs in Magento 2?

In the etc/crontab.xml file inside your module.

2. How do you create a cron job in Magento 2?

Create a class with your logic and reference it in crontab.xml with a schedule expression.

3. How do you run cron jobs manually?

Run php bin/magento cron:run and optionally setup:cron:run and indexer:reindex.

4. Where are cron job errors logged?

In var/log/cron.log or var/log/system.log depending on the error type.

5. How to avoid overlapping of cron jobs?

Use cron group configuration or custom logic in your cron class to check if the job is already running.

Magento 2 Deployment & Performance Questions – Answers

1. What are the recommended deployment modes in Magento 2?

Developer (for development), Production (for live site), and Default (not recommended for production).

2. How do you switch to production mode?

Use php bin/magento deploy:mode:set production

3. How can you improve Magento performance?

Enable full-page cache, use Varnish, optimize MySQL, deploy static content, and minimize 3rd-party modules.

4. What is static content deployment?

It compiles CSS, JS, fonts, and images into the pub/static directory using setup:static-content:deploy.

5. How do you use the config:set and config:show commands?

To set and read system configuration from CLI instead of admin: bin/magento config:set and config:show.

Magento 2 Testing Questions – Answers

1. What testing types does Magento 2 support?

Unit, Integration, Functional, and Static Tests using PHPUnit and MFTF (Magento Functional Testing Framework).

2. What is MFTF?

A powerful XML-based testing framework for automating functional UI tests using Selenium.

3. Where are unit test classes located?

In the Test/Unit directory of a module, following PSR-4 structure.

4. How do you run all tests?

Use vendor/bin/phpunit for unit/integration tests and vendor/bin/mftf for MFTF tests.

5. How to mock dependencies in Magento unit tests?

Use PHPUnit’s $this->getMockBuilder() to mock classes/interfaces.

Magento 2 Security Questions – Answers

1. How does Magento protect against CSRF?

By using form keys and CSRF validation in controller POST requests.

2. How can you secure admin access?

Use custom admin URL, 2FA (two-factor authentication), IP whitelisting, and strong passwords.

3. What is the role of Magento_Security module?

It provides features like password reset protections, session validation, and more.

4. How are encrypted values stored?

Magento encrypts sensitive config values using AES-256 and stores them in the core_config_data table.

5. How to create secure custom modules?

Sanitize inputs, use prepared SQL statements, escape output, implement ACL and follow Magento coding standards.

Magento 2 Real-World Scenarios – Interview Q&A

1. A product is not showing on frontend. What could be wrong?

Check visibility, stock status, website assignment, cache, indexers, and category enable status.

2. Admin changes not reflecting. What should you check?

Flush cache, check deployment mode, recompile, and verify config scope (store/view/global).

3. How do you fix broken CSS/JS after deployment?

Clear pub/static, re-run static-content:deploy and cache:flush.

4. Customer can’t log in. What could be the issue?

Session issues, cookie domain mismatch, incorrect credentials, or custom module interfering.

5. How to debug a 500 error in Magento?

Enable developer mode, check var/log, var/report, and server logs like Apache/Nginx error logs.