How to Hire a Hybrid App Developer

It's common for a business to need a multifunctional cross-platform application. The only solution is to develop a hybrid application. But how do you find perfect hybrid app developers? What questions should you ask them in the job interview? Find out the answers in this article.

What is a hybrid app

Let's start with the basics! Hybrid applications combine elements of mobile and web applications that are written using web technologies, like HTML, CSS, and JavaScript. Using plugins, you can allow these applications full access to the functions of the mobile device. For example, an application based on the iOS operating system uses WKWebView to display the application, while Android will use the WebView element to perform the same action.

For users, native and hybrid apps aren't distinguishable from each other: both are downloaded from a place like Apple’s App Store or Google Play, stored on a mobile device, and launched in the same way. 

Technical skills of a hybrid app developer

Now that you understand what a hybrid application is, it's time to talk about what knowledge and skills the app developer should have.

They must have a deep knowledge of HTML5, CSS3, and JavaScript, as well as one of the frameworks such as Flutter, Ionic, React Native, Cordova, PhoneGap, Xamarin. Additionally, this person should know technologies like AngularJS, Sencha, SproutCore, and jQuery Mobile.

Although hybrid applications provide a tool for building cross-platform mobile applications, sometimes a dev needs to solve specific problems. For example, when an OS-specific feature needs to be implemented. In such cases, some knowledge of native development is demanded and useful.

What should you  do before hiring a hybrid app developer

At this point, you need to answer questions such as:

• - What platforms will the app be developed for?

• - What functionality is supposed to be in the application?

• - How quickly should the application respond?

• - How much time will it take to develop the application?

• - What is the project's budget?

Without answers to these questions, it is impossible to allocate resources and hire an appropriate development team. 

Hybrid app developer job description

The next step is to create the requirements of your hybrid app devs.

For instance, let’s say you need to develop a mobile application that will track sports activity for iOS and Android. The app includes ten screens, a subscription system, a convenient design, and a high level of user data protection. The design has already been developed. Now you want to find developers to create the application and write plugins for payment through touch ID and face ID.

Responsibilities:

• - Create a mobile cross-platform application

• - Good understanding of OOP/SOLID principles

• - Provide high-quality and readable code with comments

• - Build reusable code and libraries for future use

• - Develop rich, efficient native UI with great user experience

• - Implement a Flutter/Dart application from scratch, support, and fix it

Skills and Qualifications:

• - 3+ years of development experience.

• - Strong knowledge: HTML, CSS, JavaScript, Dart, Flutter

• - Basic knowledge of languages: Java, Swift

• - Experience with Firebase

• - Understanding of SVN

• - Experience with a Third-Party Payment gateway like – Paypal, Authorize.net, HDFC, AXIS BANK, Payu (IN), eWay(AUS), etc.

• - Experience in Photoshop and Adobe Creative Cloud

• - Strong knowledge of the debugging process

• - Experience in writing reusable unit test documents

• - Strong organizational and communication skills

• - Built more than two applications available in the App Store and Google Play

• - Ability to integrate Google, Facebook, Instagram, Twitter APIs

• - Experience with Bitbucket and SVN

• - Strong problem-solving skills, as well as a self-initiative approach

• - English level: Conversational 

Q&A to hire a hybrid app developer

Now we've come to the most crucial stage - the job interview. To make this process smoother for you, we have prepared the best questions to help you find the perfect developers.

Question 1. Can we call a method from an extension of dynamic types in the Dart programming language?

Answer: No. It’s not possible because extension methods are resolved against the static type of the receiver. In Dart, extension methods are resolved statically, they’re as fast as calling a static function.

Question 2. What do you know about UX design?

What the answer tells us: Here you need to find out if the candidate has basic knowledge of UX. At first glance, the question is general, but the answer will let you see whether the engineer is good at app usability, prototyping, interaction design, and app flows scenarios.

Question 3. Can you tell me the difference between Let and Var in Swift?

Answer: In Swift language, you can declare a constant and variable using the Let and Var keywords. The main difference between the keyword let is its consistency. It is used to declare a constant variable, and the constant variable cannot be changed after its initialization.

For Example: let myWeight = 65 

We cannot change the Weight value, but we can declare a constant value using the let keyword only once.

At the same time, the var keyword is mutable and is used to declare a variant variable. These variant variables can change the run time.

For Example: var myWeight = 65

can change the value of myWeight = 75

Question 4. Can you describe the basic concepts of OOP?

Answer: Knowledge of the OOP concepts is basic. Every programmer has to know four major principles of Object-Oriented Programming: abstraction, encapsulation, polymorphism, and inheritance.

• Inheritance - is the inclusion of the behavior (methods) and state (variables) of a base class in a derived class, so they become available in this derived class. The main advantage of inheritance is that it provides a formal mechanism for reusing code and avoiding duplication. The inherited class extends the functionality of the application by copying the parent class’s behavior and adding new functions. 

• Polymorphism - is the ability to provide the same interface for different basic forms (data types). This means that classes with different functionality share the same interface and can be dynamically called by passing parameters through the reference. 

• Abstraction - is giving the object characteristics that clearly define its conceptual boundaries, distinguishing it from all other objects. The main idea is to separate the insignificant details of the implementation of the subroutine from the characteristics necessary for its proper use.

• Encapsulation - is a principle used as part of abstraction. Encapsulation refers to the structure of an object: objects encapsulate their properties and hide them from outside access. Class users interact with it using its methods, but do not have direct access to the class structure. Thus, the class abstracts the implementation details related to its structure.

Question 5. What are the types of Events in Firebase? 

Answer: The main types of events in firebase:

• child_added − it will be activated once for an existing piece of data, and every time a new user is added to the data,

• child_changed − is triggered only when data changes,

• child_removed − it will be triggered every time the child is removed.

Question 6. How can you access a mobile phone camera in Ionic? 

Answer: Ionic does not have access to the camera. But Ionic uses the plugin architecture, which is based on Cordova, so you can use Cordova plugins in the application. They give access to extensions that provide access to the camera. To do this, install the plugin using the command cordova plugin add cordova-plugin-camera. Сordova plugin defines a global navigator.camera object, which provides an API for taking pictures and for choosing images from the system’s image library.

Question 7. How do you create a widget in Flutter that looks different in iOS and Android?

Answer: By using the flutter_platform_widgets plugin, which facilitates management, but check the platform manually by doing: 

Platform.isIOS from dart:io package or 

if (Theme.of (context) .platform == TargetPlatform.iOS)

Then create and configure widgets.

Question 8. How would you debug an Ionic app on iOS?

Answer: There are three primary options:

• - Debugging using Safari. This is good for debugging a hybrid application, but cannot tell you the output associated with native plugins,

• - Open the project and build it on the device in Xcode. It will show the output of the entire device,

• - Debug with the Ionic CLI. When using ionic run, ios -l -c -s with flags will load in real-time and print logs to the console.

Question 9. How do you solve security issues?

What the answer tells us: An important aspect of developing an application is security. Security issues take a lot of time to ensure there is no risk of data loss. Mostly, hybrid applications do not have high security, and the developer should demonstrate their knowledge and share ideas on how to reduce security problems.

Question 10. How do you implement animations in React Native as smoothly and similarly as in a native application?

Answer:  It's better to apply the built-in React Native Animated API. First, you need to define specific animations using Animated.timing, Animated.spring, etc. Then provide the exact parameters to start the animation. The disadvantages of this approach might come up if you need a lot of subtle and delicate animations on the fly, which inevitably leads to a huge amount of code and support.

Instead of Animated APIs, hybrid devs often use the LayoutAnimation module, which is an interpolation API. Using it, you can call the predefined LayoutAnimations or create your own. The Layout Animation watches changes in the positions of elements between cycles of the render loop and computes the positional differences between elements at different cycles. After that, the process of interpolating the changes takes place and creates a smooth, natural animation.

Summing Up

If you need a cross-functional app that will work on different platforms whether it's a smartphone or a desktop, developing hybrid applications might be the right choice. They offer a simpler development approach, reduce costs, and are cross-platform compatible. Besides, you already know how to choose the perfect hybrid app developer. Good luck!