Top 30 Magento 2 Interview Questions & Answers

Interviews can prove to be very difficult. No matter how prepared you are or qualifications or experience you have, you can still be tricked. Every individual has fear of being asked questions that they may not know the answer to.

Therefore, it is always better to be aware of what kind of questions can be asked especially if you have no experience. If you are a Magento expert, then you must be aware of almost everything about it. But still, you can get confused right?

Don’t worry, we have curated a list of top 25 Magento 2 interview questions along with their answers. These questions have been asked in many companies before and you must prepare them to excel in your Magento 2 interview.

Magento 2 Interview Questions and Answers

Question 1. How many design patterns does Magento 2 have?

Answer: Magento has a total of 20 design patterns. These patterns include:

1. Factory Pattern
2. Singleton Pattern
3. Model View Controller Pattern
4. Front Controller Pattern
5. Registry Pattern
6. Prototype Pattern
7. Iterator Pattern
8. Object Pool Pattern
9. Service Locator Pattern
10. Lazy Loading Pattern
11. Observer Pattern
12. Module Pattern
13. Service Contract
14. Object Manager (which consist of 11+ Design Patterns)
15. Proxy Pattern
16. Factory Classes
17. Dependency Injection
18. Injectable Objects
19. Non-injectable objects
20. Active records

Question 2. What is MVC Architecture?

Answer: Magento 2 uses Model-View-Controller (MVC) is a software architecture model, primarily responsible for organizing the entire system process structure at the coding level and setting the means for system flexibility and scalability. 

MVC distinguishes three layers of software activity designed to achieve high cohesion and loosely coupled modules responsible for the operation of the Magento 2 system. 

Model: System modeling level. Its primary scope is the processing of system business rules and data persistence. 

View: This is responsible for the display layer of user information, such as product pages and contact forms. Controlled by layout files that combine blocks, containers, and UI components into pages for web browsers to display. 

Blocks are supported by PHP code to generate dynamic page content. They are often paired with easily customized phtml template files to generate HTML fragments that are compiled on a page. 

Controller: This is the layer that defines the primary actions, requests, and responses of customers that can change the status of the model and generate a view of the model layer data.

The controller controls the orchestration of page flows and form submissions. The Magento follows the standard MVC pattern, providing a good parting approach for improved modularity. 

It is important to define these concepts so that it can develop well. Even when it comes to more technical issues (coding), it is highly recommended that you have these concepts built.

Question 3. What is the command to enable or disable a Magento 2 module? 

Answer:

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

Suggested: List of Common Magento 2 Commands

Question 4. What is the main technology behind Magento 2? How is it different from Magento 1?

Answer: Magento 2 uses PHP version 7.0.2 and the above versions as a web server language. It uses MySQL version 5.6 or 5.7 for the database. The difference between the technology stack of Magento 2 and Magento 1 is provided below in the table:-

Magento 2	Magento 1
Apache 2.2 / 2.4	Apache 2.x
Nginx 1.7 or greater
PHP 5.6.x / 7.0.2 / 7.0.6	PHP 5.2.x – 5.5.x
MySQL / MySQL Percona 5.6.x or greater	MySQL
Varnish 3.x / 4.x
Redis 2.x / 3.x or Memcached 1.4.x
Solr 4.x	Solr (Only for EE)
HTML5	HTML
CSS3	CSS
JQuery	JQuery (In latest themes)
RequireJS / Knockout.js
Zend Framework 1 / 2	Zend Framework 1
Symfony
Composer
PSR – 0 / 1 / 2 / 3 / 4

Question 5. What is EAV? What does it represent?

Answer: EAV represents Entities, Attributes, and Values. Let’s look at each part and try to understand them better. 

Entity: This entity represents Magento data items such as products, categories, customers, and orders. Each entity (product, category, etc.) will have its own entity record in the database.

Attributes: Attributes represent data elements that belong to entities. For example, a product entity has attributes such as name, price, status, and so on. 

Value: A value is the simplest to understand because it is only a value linked to an attribute. For example, if an entity is a product, defined by attributes like color, size, etc. The value would then be orange, large, etc.

Question 6. What is the difference between a store and a website?

Answer: You can understand the difference between a store and a website with the help of this table. There are some parameters that are defined by a store and others by a website:

Parameter	Scope
Product settings	Default, Store View
Product prices	Default, Website
Product tax class	Default, Website
Base currency	Default, Website
Display currency	Default, Store view
System configuration settings	Default, Website, and Store view
Root category configuration	Store group
Orders	Store view
Customers	Default, Website
Category settings	Default, Store view

Let’s understand this with an example, if you have to define 2 different base currencies, you can do it in the same store but will need 2 different websites for that. 

Question 7. What are the steps to write a custom module in Magento 2? 

Answer: To create a custom module in Magento 2, you have to complete the following steps:

1. Create the module folder.
2. Then, create the etc/module. xml file.
3. After that, generate the registration. php file.
4. Run the bin/magento setup:upgrade script to install the new module.
5. Ensure that the new module is working or not.

Question 8. How can you improve the performance of Magento 2? 

Answer: Magento admin level tips to improve the performance of Magento 2– 

1. Install the latest version
2. Cache management
3. Page Caching
4. Enable flat catalog
5. Merge CSS and Javascript files
6. Clean Magento Logs and Database
7. Image Optimization
8. Have fewer modules and extensions

Server-side tips to improve the performance of Magento 2- 

1. Install a CDN
2. Choose a Magento Specialized Hosting Provider
3. SQL Configuration

Question 9. How to add a new theme in Magento 2?

Answer: The steps required to add a new theme in the Magento system are the following:-

1. Create a directory for the theme under app/design/frontend/<your_vendor_name>/<your_theme_name>.
2. Add a declaration file theme.xml and generate etc directory.
3. Also, create a file view.xml to the theme directory.
4. Add a composer.json file and registration.php.
5. Make directories for CSS, JavaScript, images, and fonts.
6. Configure your theme in the Admin panel.

Question 10. Which command is used to enable or disable a Magento 2 cache?

Answer:

php bin/magento cache:enable
php bin/magento cache:disable

Question 11. How to alter the core Magento API settings?

Answer: Steps to change the core Magento API settings are:-

1. Go the admin menu
2. Select System> Configuration.
3. On the left side of the panel under service, choose Magento Core API
4. Go to General Settings and expand it

5. Now enter the details of Default Response Charset
6. After that, enter the Client Session Timeout (secs)
7. To enable WS-I Compliance and WSDL Cache, select Yes
8. The last step is to click on Save Config Button

Question 12. What is the main difference between cache: clean and cache: flush commands? 

Answer: Cache: clean commands deletes only Magento enables cache whereas Cache: flush command deletes all the cache storage including the third party. 

Question 13. If catalog_product_flat_data is running, what are the results for that store?

Answer: When flat catalog indexing is running, the data is retrieved through EAV. Therefore performance is slowed down by both the indexing process and overhead due to EAV retrieval. The information from the products is still correct.

Question 14. How many tables are created after the generation of a new EAV model?

Answer: Six tables will be created after generation of a new EAV model-

1. module_datetime
2. module
3. module_decimal
4. module_int
5. module_text
6. module_varchar

Question 15. How to reset Magento file & directory permissions?

Answer: Run the following commands to reset Magento file and directory permissions:-

find . –type f –exec chmod 644 {} \;
find . –type d –exec chmod 755 {} \;
chmod +x mage

Question 16. What type of web servers are required for Magento 2?

Answer: Types of web servers required for Magento 2 are:-

1. Apache 2.4
2. Nginx 1 and above

Question 17.  Where is the Vendor Path file located?

Answer: The vendor_path.php is located at app/etc/ folder.

Question 18. What is the command to set up an upgrade in Magento 2?

Answer:

php bin/magento setup:upgrade

Question 19. What are the requirements for installing Magento 2?

Answer: The requirements for installing Magento 2 are:-

• You’re not on shared hosting and have your own Magento server.
• Your OS is either Ubuntu or CentOS.
• Everything is on one host (web server, database)
• Install via composer create-project.
• You’re installing to the magento2 subdirectory under your web server’s docroot (path: /var/www/html/magento)

Question 20. How is Magento 2 better than Magento 1? 

Answer: The major difference between Magento 1 and Magento 2 is that Magento 2 is faster, SEO friendly, and more user friendly than Magento 1. Magento 2 supports the latest PHP and that improves the overall speed of the site. 

It can take more orders per hour and page loads faster than Magento 1. In addition to cleaner coding and user-friendly dashboard, Magento 2 also offers meta tags functions for better SEO. They were missing in the Magento 1.

Question 21. How can you change the behavior and extend Magento’s core functionality?

Answer: There are three ways to override core functionalities:

Monkey Patches: Because Magento loads modules in a specific order, you can override the modules in the kernel and community code group by copying them into the local code group. In this case, it will rewrite the entire class. This is the least preferred method.

Rewrite: You can rewrite a function by specifying a class in the configuration file to rewrite an existing class. In this case, you can extend the parent class and rewrite only one function.

Observer: Magento throws events when a particular operation is completed. If an event occurs before or after the action you want to interact with, you can intercept and modify it. This is the preferred method.

Question 22. How can you count the items in a collection?

You can count items in a collection using getSize(). This function does not load the collection each time to calculate the item but stores it. So whenever you need that value, you don’t have to recalculate it. In addition, it uses the SQL COUNT() function to speed up the counting process., this value may become inconsistent.

Question 23- What are the different deploy modes and what are their differences?

Answer: There are mainly 3 deployment modes in Magento 2- 

Developer- In this mode, all files in pub/static/ are symbolic links to the original file. An exception is thrown and the error is displayed on the front. This mode makes page loading very slow but makes debugging easier because it compiles and loads static files each time. You can still enable caching.

Default- It is a state between production and developers because files are generated when needed. That is, css files are generated using some files in multiple locations. These files will be created only when they are required by the front-end and they will not be created again next time they are not required. 

Production- Enable this mode for all magento 2 sites in production, since all necessary files are generated and placed in the pub/static folder.

Question 24. What is dependency injection and what are its advantages?

Answer: Magento 2 uses dependency injection to replace the features provided by magento class in magento 1.x. 

Dependency injection is a design pattern that allows an object to declare its dependencies to the external object b that provides these dependencies. Dependencies declared by a are typically class interfaces, and dependencies provided by b are specific implementations of those interfaces. 

This allows loose code coupling because an object no longer has to worry about initializing its own dependencies. Object b decides to provide the implementation of Object a based on the desired configuration or behavior. 

This is an important concept that extension developers understand because it forms the basis of how magento composes its classes. 

Question 25. What is a factory class and how does it work in Magento 2?

Answer: Factory classes are generated when code is generated. They are created automatically for models that represent database entities.

Factory classes are used to create, get, or change feature records without directly using Object Manager, as Magento does not encourage direct use of it. These classes do not need to be defined manually, but they can be defined, in case you need to define specific behaviors.

Hope you find the list of these Magento 2 interview questions useful. In case you have any doubt and want us to add more questions in this list, then do let us know in the comments below.

Official support for Magento 1 is ending soon. ServerGuy is offering Magento 1 EOL support. Do contact us for more details.

Question 26. How to enable Maintenance mode in Magento?

Answer: You can enable Maintenance mode in Magento by creating a file named maintenance.flag, then uploading it to the Magento home directory containing the following commands.

$maintenanceFile = 'maintenance.flag';     
if (file_exists($maintenanceFile)) {  
include_once dirname(__FILE__) . '/errors/503.php'; 
exit;  
}

Question 27. How to Add a Blog to Magento?

Answer: There are 2 options to add a blog to your Magento: Either using the Blog built-in module or by setting up your own custom-made module. The Magento Blog extensions comes with a lot of features that make it very useful, but if you want even more customization then you may want to build your own custom blog module.

Question 28. Is it possible to have more than one grid in Magento?

Answer: Yes it is possible to have more than one grid in Magento.

Question 29. Explain handles in Magento?

Answer: Handle controls the structure of the page to be displayed. It decides which block will go where in a page when it’s called. Handle is called whenever a page loads, and each call to handle is unique.

Question 30. Explain compilation feature in Magento?

Answer: Compilation feature allows us to compile all Magento files to create a single include path to increase performance.