Top 20 Firebase Interview Questions and Answers for Developers

Hello guys, if you are preparing for Firebase Developer Job interview or interviewing for a Job where Firebase skills are needed and you need Firebase interview questions to prepare quickly and better then you have come to the right place. Earlier, I have shared HTML Questions, CSS Questions, and JavaScript Questions and tutorials and today I am going to share best Firebase Questions with answers. If you have used Firebase for few months or worked as Firebase developer then most likely you know the answers of these questions but if you struggle then you can always join any of these best Firebase courses to further learn  and revise essential Firebase concepts. 

If you have interest in understanding Firebase more than you do then you will have every reason to go through this article. Apart from understanding Firebase, you have to be always ready for any interview in regards to this particular area. 

Being ready means that you have to be familiar with what goes on in that interview. For that reason, you have to know the questions that are normally asked and thereafter find the answers to those questions. Below are the questions that are commonly asked in Firebase interviews.

20 Firebase Interview Questions With Answers

Here are the 20 frequently asked Firebase interview questions and answers. I have tried to cover essential Firebase concepts with these questions and you can use this list to quickly revise those. Though if you see a particular topic is missing, feel free to suggest in comments. 

1. What is Firebase and who is the founder?
Answer: it is a platform used for building IOS, Web and Android applications. It was founded by James Tamplin and Andrew Lee in September 2011.

 

2. What are the advantages of Firebase?
Answer:

• Variety of useful services to choose
• Simple control dashboard is offered
• It is user friendly
• Data is real time

 

3. What are the features of Firebase?
Answer: the features of Firebase include:

• Authentication
• Real-time Database
• Hosting

 

4. What does FCM and GCM stand for?
Answer: FCM stands for Firebase Cloud Messaging while GCM stands for Google Cloud Messaging.
 

5. What are the Firebase events?
Answer: Firebase has five events which are as follows:

• Value
• Child_added
• Child_changed
• Child_moved
• Child_removed

 

6. What is the difference between Firebase and MongoDB?
Answer:

• Firebase was developed by Google in 2012 while MongoDB was developed by MongoDB Inc. in 2009.
• Firebase is a commercial database while MongoDB is an open-source database.
• In Firebase the Map Reduce technique is not supported while MongoDB supports Map Reduce techniques.
• Firebase is better suited for smaller applications while MongoDB is better suited for large-scale applications.
• Firebase is not very secure while MongoDB has good security.
  

 

7. What are the filtering methods in Firebase?
Answer: Firebase filtering methods are:

• startAt() method
• endAt() method
• equalTo() method
  

 

8. What are the Real time database limits in Firebase?
Answer: The Real time database limits are:

• Simultaneous connections added are 100,000.
• Simultaneous responses sent from a single database are 100,000/second.
• The number of cloud functions triggered by a single write is 1000.
• The size of database write that triggers a function is 1 MB.
  

 

9. How is Firebase Console Language determined?
Answer: The language setting for the Firebase console is based on the language selected in your Google account settings under "Account Preferences" > "Language and Input Tools". The Firebase console is available in the following languages:

• English
• Brazillian Portuguese
• French
• German
• Indonesian
• Japanese
• Korean
• Russian
• Simplified Chinese
• Traditional Chinese
• Spanish
  

 

10. What Roles And Permissions Does The Firebase Console Support?
Answer:

• The Firebase console and Google Cloud console use the same underlying roles and permissions. At a high-level, these are owner, editor, and viewer.
• A project owner can add other members to the project, link other Google services such as Play/AdMob/AdWords/BigQuery and has full edit access on the project.
• A project editor has full edit access on the project.
• A project viewer has only read access on the project. Note that our UI currently does not hide/disable edit UI controls for project viewers, but these operations will fail for users with viewer role.
  

 

11. Why Is Firebase Analytics A Recommended Part Of Using Firebase Products?
Answer:

• Firebase Analytics is a free and unlimited analytics solution that works with Firebase features to deliver powerful insights. It enables you to view event logs in Firebase Crash Reporting, notification effectiveness in Firebase Notifications, deep link performance for Firebase Dynamic Links, and in-app purchase data from Google Play. It powers advanced audience targeting in Firebase Remote Config, Firebase Notifications, and more.
• Firebase Analytics acts as a layer of intelligence in the Firebase console to provide you with more actionable insights about how to develop a high quality app, grow your user base, and earn more money.
• Firebase Analytics is a part of the core Firebase SDK. Integrating Firebase Analytics is fast and easy.
  

 

12. How can we create a unique key and use it to send data in Firebase?
Answer: We can use push() to establish a unique key in the Firebase database, and then add child nodes to that key. When you return to that activity in the future, check to see if the parent node is still present. Save the parent node key and use it to save new child nodes if the node already exists.

 

13. What are the prerequisites for linking play/admob/adwords/bigquery to Firebase Project?
Answer:

• For linking your Play account, you need to be both a Firebase project owner and a Play account owner.
• For linking your AdMob app, you need to be both a Firebase project owner and an AdMob administrator.
• For linking your AdWords account, you need to be both a Firebase project owner and an AdWords administrator.
• For linking your BigQuery project, you need to be the Firebase project owner.
  

 

14. How Do you Create Closed Funnels?
Answer: In Firebase Analytics, the Funnels page only shows open funnels. To create closed funnels, the events that the developers create have to enforce this. For example, if the following flows are possible:

Flow 1: Screen A, Screen B, Screen C, Screen D
Flow 2: Screen X, Screen Y, Screen C, Screen D

You could log the following events

Flow 1 → A, B, C_1, D_1
Flow 2 → X, Y, C_2, D_2

Each set of these creates a closed funnel in Firebase Analytics. You can then create an audience of users who log all events in each Flow.

 

15. How do you control how your Analytics Data is shared with rest of Firebase?
Answer: By default, your Firebase Analytics data is used to enhance other Firebase and Google features. You can control how your Firebase Analytics data is shared in your project settings anytime.

 

16. What is the use of on() method in Firebase?
Answer: on() method is used to retrieve data.

 

17. What is the use of child_changed method?
Answer: it is an event type which is triggered when the data has changed.

 

18. What is the use of child_removed method?
Answer: it is an event type that is triggered when we want to remove data.

 

19. What is Cloud Firestore?
Answer: Cloud Firestore is a flexible and scalable NoSQL cloud database. It is used to store and sync data for client and server-side development.

 

20. What are the functions used for sorting data?
Answer:

• orderByValue()
• orderByChild()
• orderByKey()
  

 

That's all about common Firebase Interview Question for developers. Lastly I can say at least you have found what you have been looking for. I hope you have found the questions to be engaging and interesting. You can visit the article once again if you feel you have not understood to the level you want. 

Going through questions several times plays a great role in boosting your confidence even further. Make sure you put yourself in the best place possible to pass your interview and you will surely be happy with yourself in the end. I wish you good luck.

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If you liked this list of the Top 20 Firebase and Firestore Interview Questions with Answers, feel free to share it with your friends and family. You can also drop a comment if you have any doubts regarding Firebase and Firestore and we will get back to you as soon as possible.

P. S. - If you want to learn Firebase in depth and looking for resources then you can also check out these best Firebase and Firestore courses to start with. The list contains best online courses to learn Firebase and Firestore for Software developers.