Firebase Interview Questions & Answers (2025)

Firebase is a Google’s platform which helps to build and develop web applications, IOS applications, and Android applications. It adds developer to speedily develop the apps with maintaining the high quality of applications and allows you to grow your business to a higher extent. The platform of Firebase can actually help to empower the application's backend and static hosting. It also contributes to user identification. Real-time database which the firebase of words and many authentication types is advantageous for the applications.

Firebase was founded by James Tamplin and Andrew Lee in the year 2011 in September.

The benefits offered by Firebase are enormous which includes its user-friendly nature along with its simplicity. It offers multiple useful services for the applications. It's very decent control dashboard is helpful and its real-time data allows to observe every change instantly that occurs in real-time. The complicated configurations are no more needed in Firebase. It storage allows us to upload raw files on the cloud and read it from there itself.

Firebase provides a number of features that are advantageous. The most convenient features of Firebase include Hosting and Authentication. Firebase hosting grant our web applications swift and safe hosting, and so is also provided you are content. Authentication of users is an effective feature of the Firebase provided by Google. Another great feature of Firebase involves a Real-time database that allows us to monitor the changes happening that get uploaded automatically. Fiber storage also contributes up to a greater extent by providing cloud storage for uploading raw files and able to read it.

The main restriction in the Firebase is its price since the free plan of Firebase is limited. It allows only 1000 MB of storage and provides just 50 connections. The other limitation of firebase is that the data is not hosted by you. It is hosted by Firebase. The root access to the exact location of the storage of your data is not under your control. By a single write, 1000 cloud functions are triggered

The language in the Firebase Console is determined on the basis of the selected language from the Google account setting. It is as per the language opted from 'Language and Input Tools' in 'Account Preferences'. Firebase is feasible in many languages which include English, German, French, Korean, Russian, Spanish, Traditional Chinese and few more. Language is one of the factors that provide ease to users from different countries and continents around the world.

The Firebase Console is supported by the latest versions of browsers including Chrome of Google, Safari of Apple, Firefox of Mozilla and Internet Explorer of Microsoft. Firebase Console is supported by desktop browsers however it is currently not completely supported on mobile browsers.

The biggest advantage of Fibre Analytics is that it is free and provides limitless analytics solution that functions with the features of Firebase for more effectiveness. It helps you to keep the visible track of the events in Firebase. Its audience targeting ability is very profitable and suitable for growth in businesses. Firebase Analytics helps you to get access to actionable steps for developing applications with high quality. It allows the business to grow the user base and gain maximum profit by earning money. It is fast to integrate the Firebase Analytics, and also it is simple to do so.

GCM is an abbreviation to the term ' Google Cloud Messaging '.

FCM is an abbreviation to the term ' Firebase Cloud Messaging '.

FCM is basically the recent version of Google Cloud Messaging ( GCM ). FCM has the core infrastructure of GCM, making it easier for cloud messaging development.

The Firebase Storage helps in easily sharing the data between the GCP project ( Google Cloud Platform Project ) and Firebase. It allows to rapidly start going with the Firebase storage with no more need of putting the credit card in. Firebase storage creates a space in the Google Application Engine.

The reason for being unable to create that space is known to depend on two causes which will prevent you from using the Firebase storage. The first reason could be that the project which is transferred from Google Cloud Platform ( GCP ) has projects with domain prefix. The second reason is that the project which is transferred from Google Cloud Platform ( GCP ) has a Slave data store application.

The limits of Real-time database are as follows.

A database of size 1 MegaByte ( 1 MB ) triggers a function. 100000 connections are added as simultaneous. 100000 responses are sent per second simultaneously through a single database.

The use of Sha-1 is done for simplifying the configuration of Google Sign-In with the help of authentication in Firebase. Sha-1 is not always needed. Its need arrive when you use Firebase invites or the FDL i.e. Firebase Dynamic Links. When one is not using these factors that are mentioned above, you don’t need access to Sha-1.

A project is a vessel containing applications of the web, android, and iOS. Firebase projects are the projects presented by Google which uses services of Firebase. The projects that are available in the Firebase Console are available also in the GCP ( Google Cloud Platform ). The projects are also accessible in the Google APIs consoles.

When a project is deleted from any console, it gets deleted from all the consoles. Project’s distinctive identifiers are shared over consoles and project’s permissions are also shared over consoles. You get the ease to share with users the data overall platforms of Android, web, and iOS. This allows users to enjoy the same experience on all the devices they are using.

To manage every version of the apps that use Firebase are attached to a Firebase project so that the apps could be managed from Firebase Console. Database and configuration between apps from different platforms are features that are supported by the Firebase project.

It is preferred to add web, iOS and android application versions into one single project.

Firebase Could Function is a Google analog that is taken into used to develop applications which are serverless. The Cloud Functions for firebase allows running the code of backend itself as a reaction to the HTTP requests and Firebase's triggered events. There is no more need for managing and increasing one’s own server since the data is being kept in Google's cloud which runs in a safe and managed atmosphere. TypeScript and JavaScript can be used for writing the functions. The Firebase features and Google Cloud feature’s events generated by them, the functions can react to these events including Real-time database triggers and Cloud Storage triggers.

After deploying the code written in JavaScript what TypeScript to a server of Firebase along with a command, it automatically carries on with the process of scaling the computing resources that will help to match the patterns of usage of the users. One did not take any tension regarding the server configuration, regards to the Cloud Functions. The function can be deployed with an HTTP request as well and the function will automatically start to be managed by the service of Google. All the connections are cleaned up as the function gets deleted and the event provider also gets erased.

To import an existing firebase.com app and an existing Google project to a single firebase project, the firebase.com app should be upgraded to a firebase project.

To use firebase invites in the firebase project with OAuth client which is already registered to some other Google project, OAuth client could be added to the whitelist client IDs from Google’s sign in methods

The permissions and roles used by the Firebase Console and GC Console ( Google Cloud Console ) are similar. At an upper level, there are project viewers, project editors and project owners. Members are added to the project by a project owner. The project owner can also link other services of Google like AdWords and AdMob

Also, a project owner has complete access to the edit in the project. The complete access to the edit in the project is also available to the project editor while the project viewer has access in the project only to read. Permissions differ for a project owner, a project editor and project viewer. All these have their own different roles.

The use of the Set method is that it is used for writing or replacing the data specifically.

No. There is no need to use any other service of Firebase for using FCM ( Firebase Cloud Messaging ). It could be used as a strong and stable element.

For creating close funnels, the events created by the developers need to enforce this. Understanding with an example, if these floors can happen. Flow 1: Screen X, Screen Y, Screen C, Screen D. Flow 2: Screen A, Screen B, Screen C, Screen D. Only the open funnel is seen in the funnel pages of firebase analytics. It does not show the closed funnels.

Various types of events available in Firebase. These are child_added, child_changed and child_removed.