How to Build a Backend for a Mobile App?

In this article, you’ll learn what a mobile app backend is and what you need to know to create your backend.

We look at the differences between a backend and a frontend, different backend types, learn more about mobile backend functionalities and the costs of developing a backend.

Reading: How to create a backend for an app

Finally, we will learn how to create a backend for a simple mobile application on Back4app – one of the best MBaaS providers.

Differences between a frontend and a backend

The terms frontend and backend refer to the separation of concerns between the presentation tier and the data access tier.

The easiest way to understand their differences is to visualize an iceberg. The front end sits above the waterline and is all a user can see and interact with. The backend, on the other hand, is the part of the iceberg that lies under water. It’s the underlying logic that drives the business.

Frontend

A frontend is a graphical user interface of a website, mobile app, or other type of client that with which a user can interact with. The frontend encompasses all visual aspects of an application, including design, menus, text, images, videos, etc. For most projects, it accounts for about 20% of the total effort and is non-repetitive.

Frontend developers need to Take care of:

• Responsive design
• App performance
• Cross-browser compatibility
• Accessibility
• SEO Optimization

Web frontends are usually implemented using tools like HTML, CSS, JavaScript, and WebAssembly. Native Android apps are written in Java/Kotlin while native iOS uses Objective-C and Swift.

In recent years, many frontend developers have adapted tools such as React Native, Vue and Svelte Native to further simplify the development process and get the same code base to work on different platforms.

Frontends can be “provisioned” for services like Google Play, App Store, Vercel, Netlify.

Backend

Backend or server side development is the practice of data access layer development. The backend is the connection between the database and the frontend. Most backends provide an application-level interface (API) that a frontend can use to retrieve and store data.

Data is usually exchanged in JSON or GraphQL format. A backend typically accounts for about 80% of the work and is repetitive. For example, almost every project requires authentication, authorization, database management, and so on.

Backend developers are responsible for:

• Database management
• Application business logic
• Scalability, High Availability
• Security Concerns & Backups

Backend developers typically work with programming languages ​​like Python, JavaScript (Node.js) , Ruby, C#, Java and Go. At the time of writing, the most popular backend architecture is Model-View-Controller (MVC), which has been adopted by many web frameworks such as Django and Laravel.

The most important component of a backend is its database. We have different types of databases, which we can group into three general categories:

• SQL databases
• NoSQL databases
• Multi-paradigm Databases

They each have their pros and cons that should be considered when starting a project.

A backend can be deployed on different platforms depending on the desired level of abstraction. For example, you can use your own server, IaaS (AWS, GCE, Azure), PaaS (Heroku, Digital Ocean App Service), or BaaS (Back4app, Firebase, AWS Amplify).

Read more Learn more about backend development of mobile apps.

What is a mobile app backend?

A mobile application backend is the part of the app that runs on a server and not on the device itself. The backend provides the functionality the app needs to store and manage data, authenticate users, process and analyze data, and communicate with other systems or services.

A backend can take many forms, such as B. a server running on a cloud service, a database or an API. It provides the necessary infrastructure and tools that the app needs to function properly and enables the app to provide a rich and engaging user experience.

What functions does a mobile backend offer?

A backend for a mobile app usually offers the following functionalities:

• Saving and managing data
• Processing and analysis of data
• Authentication and authorization
• Synchronization between multiple devices
• Ability to integrate with other systems and services
• Manage server-side tasks
• Analytics & Monitoring
• Push notifications

Does a mobile app need a backend?

Short answer: If your app works locally (without an internet connection), you usually don’t need a backend, but that doesn’t mean your app can’t benefit from a backend.

To get better About this answer To understand this, let’s take a look at some of the apps we use on a daily basis.

Apps that don’t require a backend:

• Calculator
• Calendar and clock
• Camera and gallery e
• Voice Recorder
• Single player games

Apps that have a backend:

• Ecommerce -Apps – a backend is required to track inventory, process orders, etc.
• Transportation apps – a backend allows for ticket processing, information about delays, etc.
• Messaging- Apps – a backend is used to transfer news from one device to another
• Weather apps – a backend is required to get current weather information

Let’s think about it now how a backend could enhance the apps listed above:

• Calculator – could use a backend to offload complex calculations to a remote server
• Calendar and clock – could Store events in a database and sync them between devices
• Camera – could use a backend service to add distortion, lighting, etc. Backend service for noise reduction
• Individual lplayer games – could store user results in a database and display a ranking

Due to the great benefits that backends have to offer, almost all mobile applications can recognize a b. When it’s not about storing data, the backend allows mobile apps to collect analytics, send push notifications, monitor apps, collect crash reports, and more. If you want to be successful, you most likely need a backend.

What are the backend types?

Depending on the type of your application, there are several backend types you can choose from. In general, we can classify them into three groups based on their level of abstraction:

1. Software as a Service (SaaS) or Third-Party Services
2. Mobile Backend as a Service (MBaaS)
3. Custom backends

Let’s take a look at each one of them.

Software as a Service (SaaS) or third party services

Software as a Service (SaaS) is a software delivery model in which a software application is hosted by a third party and made available to customers over the Internet.

SaaS solutions typically require their customers to pay a monthly or annual subscription fee. This backend type is the easiest to use and allows you to get your backend up and running in a few clicks.

The disadvantage of this backend type is that you most likely won’t find any SaaS that can do this meets all the needs of your project. In order to create a real backend, you probably need to combine several SaaS solutions.

Some examples of SaaS are:

• WordPress (content management system)
• Mailchimp (management software and email marketing)
• Salesforce (customer relationship management software)
• Shopify (ecommerce platform)
• Dropbox (File Hosting)

Mobile Backend as a Service (MBaaS)

Backend as a Service (BaaS) is a platform that automates and takes care of the backend side of development Support of the cloud infrastructure.

It also offers features such as user management, email notifications, push notifications, cloud code capabilities, social media integrations, file storage and payments.

It enables Developers Focus on the core business and building the frontend without worrying about the underlying backend and infrastructure. The front end is usually developed via specialized APIs and SDKs offered by the BaaS provider. This makes apps less complex and easier to maintain.

Benefits of using a backend-as-a-service include faster development speed, lower engineering costs, and focus on core business.

See also: 20 simple methods to make money with a website

Some examples of BaaS are:

• Back4app
• Firebase
• AWS Amplify
• Apple Cloudkit

Want to learn more about BaaS and MBaas? Take a look at What is BaaS?

Custom Backend

A custom backend is the most powerful and flexible option. It gives you complete control and allows you to implement features that cannot be implemented with a SaaS or MBaaS solution.

Its main disadvantage is the cost and the construction time.By using this approach, you also take full responsibility for the performance and security of your backend.

Building a custom backend usually takes months and requires an experienced backend developer or even a team of backend developers.

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Popular frameworks for building custom backends:

• Django
• Laravel
• Express.js
• Ruby on Rails
• Spring Boot

For more information on backend frameworks, see Top 10 Backend Frameworks.

How much does it cost to build a mobile app backend?

There is no easy formula to calculate the cost of a mobile app backend. The cost varies depending on the complexity of the app, number of features, scalability, performance, etc.

SaaS Cost

SaaS is usually the cheapest option you can go for for. SaaS products typically follow a straightforward pricing model with monthly or annual subscription fees. Some SaaS providers also offer different pricing tiers depending on the size of your business.

MBaaS Cost

Building a backend with MBaaS is really cheap compared to a custom backend. This allows you to significantly reduce development costs and not worry about infrastructure or hiring a team of specialized backend engineers. This will save you a lot of money!

Most MBaaS providers have different price levels depending on the size of your app. By using MBaaS, you can expect to pay anywhere from $15 to $500 per month.

Custom backend costs

Custom backend development is the most expensive option. If you choose this option, you will need to assemble a team of experienced developers and take care of your backend infrastructure.

Prices for building a custom backend generally range from a few thousand dollars to tens of thousands of dollars depending on project requirements.

Since implementing a custom backend is a difficult task, companies usually outsource this to companies specializing in software development.

How to build a backend for a mobile app with MBaaS ?

In this section of the tutorial we will look at how to use Back4app to develop a backend for a mobile app.

What is Back4app?

Back4app is one of the best open-source backend-as-a-service (BaaS) solutions on the market. It offers its users an extensive range of features and benefits that enable developers to quickly create web and mobile applications.

By using Back4app, you can focus on the core business instead of worrying about the backend or the underlying infrastructure.

The solution has a feature-rich and easy-to-use dashboard to use and a command line interface (CLI). They also provide SDKs for all your favorite tools like Flutter, React Native, Node.js, Angular, Android, iOS and more!

Back4app’s main features include:

• Spreadsheet-like database
• REST and GraphQL APIs
• Live queries
• Authentication (including social authentication)
• Scalable hosting
• Push and Email Notifications

For more information about their features, see Back4app Features.

Back4app follows a simple and straightforward pricing model suitable for an app of any size. They offer a generous free plan (no credit card required) that’s great for prototyping and testing the platform. It includes:

• 25,000 requests
• 250 MB data storage
• 1 GB transmission
• 1 GB file storage
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  For more information on Back4app pricing, see the pricing page.

  Project Introduction

  This is what we’re going to do Building a backend for a simple messaging app. The app allows editors to create, update, and delete articles. To make management as easy as possible, we will enable the Back4app admin app.

  We take care of the backend security and show how to use the backend REST API. The backend is built with minimal code effort.

  Prerequisites:

  • Basic understanding of backend as a service (BaaS)
  • Basic understanding of databases (and relationships between models)
  • Basic understanding of HTTP requests and responses
  • Understanding JSON syntax

  Goals:

  By the end of this tutorial you will be able to:

  • Create and deploy a simple backend on Back4app
  • You can Structure your own database
  • Understand the basics of Parse platform security
  • You know how to perform CRUD operations via the REST API

  Create App

  For the following steps you need a Back4app account. Otherwise, if you already have it, log in and register for the free account.

  In order to work with Back4app, we first need to create an app. When you log into your dashboard, you will see the list of your apps. Click “Create new app” to create a new app.

  

  Give it a custom name and then click “Continue”.

  Back4app will take a moment to prepare everything that is required for your app, such as database, application layer, Scaling, Backups & Security.

  Once your application is ready, you will be taken to your app’s dashboard.

  

  Database

  In this section of the tutorial we will create all the required database models.

  As mentioned in the project introduction, we will build a simple messaging app. Our database will consist of the following models:

  • Article represents a news article.
  • ArticleCategory represents an article category (eg, sports, entertainment). An article can belong to a category.
  • ArticleTag represents an article hashtag (e.g. cosmetics, health, beauty). An article can have multiple hashtags.

  This database structure will later allow us to filter the articles by categories or tags. Let’s draw an Entity Relationship Diagram (ERD) to better understand the relationships between the models:

  

  Now let’s actually build the models.

  Start by creating the ArticleCategory -model. Click “Create Class” in the top left, name it Item Category and add the following fields:

  +-+-+-+-+ | data type | name | Default value | Required | +-+-+-+-+ | string | name | | yes | +-+-+-+-+ | string | Description | | no | +-+-+-+-+ | Pointer -> Users | Author | | yes | +-+-+-+-+

  See also: How to Integrate Motion Into Your Website Design

  Next, create another class called ArticleTag with the following details:

  +-+-+-+-+ | data type | name | Default value | Required | +-+-+-+-+ | string | name | | yes | +-+-+-+-+ | Pointer -> Users | Author | | yes | +-+-+-+-+

  Finally, create another class called Article with the following fields:

  +-+-+-+-+ | data type | name | Default value | Required | +-+-+-+-+ | string | Title | | yes | +-+-+-+-+ | string | Description | | no | +-+-+-+-+ | string | content | | yes | +-+-+-+-+ | Pointer -> Item Category | Category | | no | +-+-+-+-+ | Relation -> ArticleTag | tags | | no | +-+-+-+-+ | Pointer -> Users | Author | | yes | +-+-+-+-+

  That’s it for the database architecture. Now let’s add some sample data.

  To make things a little easier, I’ve generated some data that you can import. To import a data set, select the class on the left side of the screen and then click on the three dots on the right side of the screen. Choose Import > Class Data and select the appropriate file.

  

  To download the JSON datasets, navigate to the back4app mobile GitHub repository, click “Code” and then ” Download ZIP”.

  Import the JSON files in the following order:

  1. User
  2. ArticleCategory
  3. ArticleTag
  4. Article

  Admin Panel

  To make administration a bit easier, let’s enable the admin app. The Admin App is a web browser-based tool for managing app data through a non-technical user interface.

  Navigate to your app dashboard, click More > Admin App and then click the Activate Admin App button.

  

  Choose a username and password. I’m going with:

  Username: admin Password: complexpassword123

  Then select a domain name that you want to use to access your admin panel. I’ll take:

  mobile-backend.admin.back4app.com

  Great, you can now login to your admin dashboard at the selected domain.

  To learn more For Back4app Admin App information, please refer to the official docs.

  Securing the App

  To make our app secure we need to do the following:

  1. Prohibit clients from creating database classes.
  2. Change class-level permissions (CLPs) for user models.
  3. Change CLPs for each model we create.

  Deny creation of client classes

  To disallow creation of client classes, navigate to your “App Settings” > “Server Settings” > “Core Settings” > ” Edit”, scroll down to the bottom of the page and uncheck “Allow creation of client classes”.

  Change User Model CLPs

  Select your user model in the Database tab and click the three dots on the right side of the screen > Security > Class Level Permissions “. Then click on the gear icon and change it to “Advanced”. Disable everything except fetch and create like this:

  

  Change CLPs for each model we create

  Do the same for all your custom models (item, item category and item tag). This time disable everything except “Read” and “Search” for the public group like this:

  

  This way only unauthenticated users can find and read the articles.

  For more information on security, take a look at Parse Security.

  API testing

  In this section of the tutorial, we will test our API using the built-in API console .

  To open the REST API console, navigate to your app’s dashboard. Select “Console” in the “API” section and then “REST”.

  

  Due to our ACL/CLPs, make sure you tick “Use master key?”. for the requests to succeed.

  Retrieve

  Objects can be retrieved using the GET request type. For the endpoint, use classes/ e.g. Classes/Items and click the Submit Query button at the bottom of the page.

  The response will look something like this:

  { “results”: [ { “objectId”: ” oRwkdx7KgX “, “title”: “The 2022 voting is over!”, “description”: “The voting for 2022 is over, the new major is…”, “content”: “Lorem ipsum dolor sit amet.. .”, “category”: { “__type”: “Pointer”, “className”: “ArticleCategory”, “objectId”: “FYxzrBlCBC” }, “author”: { “__type”: “Pointer”, “className”: ” _User”, “objectId”: “UZ76K07znv” }, “createdAt”: “2022-12-13T09:09:04.845Z”, “updatedAt”: “2022-12-13T09:09:13.297Z”, “tags” : { “__type”: “Relation”, “className”: “ArticleTag” } }, … more results… ] }

  If you want to get a specific result or filter the query set, throw have a look at it in the docs.

  Create

  To create a model instance, select the POST request and send it to class/, e.g . Classes/Articles. POST requests require you to provide query parameters. For example:

  { “title”: “Another article”, “content”: “This is another test article added via the API”, “category”: { “__type”: “Pointer”, ” className” : “ArticleCategory”, “objectId”: “pPGdxPAxQA” }, “author”: { “__type”: “Pointer”, “className”: “_User”, “objectId”: “LFAf3yD8w0” } }

  Answer :

  { “objectId”: “yAbmJ0sRZT”, “createdAt”: “2022-12-12T17:18:32.922Z” }

  Update

  To update a model, select the PUT request type and send it to class//