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Android Developers

How to Hire an Android Developer

Google’s Android platform continues to be the most popular mobile operating system on the market, and it’s going to keep growing. For example, in 2019, 1.19 billion Android devices were sold! The analysts at International Data Corporation (IDC) predict that the number of devices will increase to 1.3 billion units by 2023. And the share of such devices in the market will rise to 87.4%.

The popularity of the Android operating system is due to its openness for both users and developers. Free and open - these are the two factors that allowed Google to increase Android's share of the mobile device market.

What tools do developers use to create applications for Android

The main programming language for mobile development on Android is Java. Now Google is actively promoting Kotlin as a language that can replace Java. Kotlin is a younger language with some developer-friendly features.

Creating a simple application consists of several stages:

  • - Creating a project in Android Studio,

  • - User interface creation,

  • - Adding activities, navigation, and actions,

  • - Test-driving of the app in the emulator.

Android Studio is the official development environment (IDE) for Android, it runs on Windows, macOS, and Linux, although you can use other environments besides Android Studio.

What are the components of the application

The Android application consists of four components. Each component is an entry point through which the system or user can access:

  1. Activity is elements of the interactive user interface,

  2. Service is a universal entry point for keeping the application running in the background,

  3. The broadcast receiver transmits the intentions from several applications to several participantsA content provider manages the shared data set of an application from a file system, SQLite database, the Internet, or another repository.

What technical skills are important for an Android developer

An Android developer’s role involves the creation, updating, and improvement of various mobile applications and software for smartphones, e-books, tablets, game consoles, and other devices that run on the Android OS.

Android programmers are involved in several types of work:

  • - Writing software code,

  • - Software testing,

  • - Analysis of technical requirements and prototypes, user interfaces that are received from customers and designers,

  • - Making recommendations in technical specifications, choosing ways to solve the most important tasks,

  • - Downloading created software products to stores or any other sites,

  • - Make edits and create updates for programs,

  • - Engage in analytics, seek innovative solutions to improve existing software products.

Among the skills that Android developers need are:

  • - Knowledge of the principles of OOP,

  • - Experience with Java or Kotlin,

  • - Practical skills of working with View Group and Android SDK, as well as with Java Core, RxJava, Dagger, Android Framework, and REST,

  • - Understand the principles of UI / UX design, as well as SQL and SQLite,

  • - Experience with Google Play,

  • - Be able to correct errors in someone else's code.

Like other technicians involved in working with software, Android developers can be divided into 3 (entry, middle, senior) levels depending on experience and skills.

How much does it cost to hire an Android Developer 

Specialists engaged in the creation of products for the Android OS are in great demand both in the USA and Europe.

Demand for highly skilled Android developers exceeds supply. This creates a shortage in the market. Before you start looking for an Android developer, you need to make one key decision: who exactly is needed for your project, an individual freelancer, or a professional developer?

If you hire a freelancer to develop the application, you run the risk of waiting forever for the finished product. Developing software for Android using a freelancer is a pretty risky decision if you have an average budget. If you entrust the work to a professional developer, you typically do not need to worry about quality and deadlines.

Android developer job description

Now you have made a decision and are ready to find a professional developer. Your first step should be to form a quality and attractive job offer. Describe what your company does, how long you have been in the market, and what the main benefits of working with you will be for the developer. 

Now it is necessary to determine what exactly the developer should perform. Talk to your managers and formulate expectations for the product that the new developer will work on. 

Personal qualities are what distinguishes a great team member from a bad one. You need to pay attention to such essential personal skills as

  • - Analytical thinking

  • - Responsibility

  • - Attention to details

  • - Creative skills

  • - Ability to meet deadlines

  • - Teamwork skills

  • - Problem-solving skills

  • - Focus on results

  • - A constant desire to learn new technologies and tools

Now it's time to write a job description. The below example assumes you have been successfully running your own business for several years. You are good at sports and conduct personal training for your clients and have now decided to reach a new level - to launch a mobile application and to monetize it by using a paid subscription for individual courses. As we already know, Android is the most popular mobile platform, so you need an Android developer.

Job description: middle Android developer


  • - Develop mobile applications on the Android platform

  • - Offer technological, and architectural solutions to implement them

  • - Maintain applications, continue to develop and improve applications

  • - Perform payment system integration

  • - Write reusable, testable, and efficient code

  • - Test Android app

  • - Analyze and resolve technical and application problems

  • - Develop the concept and functionality of the application

  • - Develop UI and UX application concepts

  • - Ensure the app meets Google’s guidelines

Skills and Qualifications:

  • - 3+ years of Android development

  • - Languages: Java/Kotlin

  • - Platform: Android Studio

  • - Libraries: Retrofit, Glide

  • - Experience with Dagger 2, MVP/MVVM architecture, Android Architecture Components

  • - Strong knowledge of Rest API, JSON, XML, SQL

  • - Deep knowledge of Android UI design principles and patterns

  • - Strong knowledge of design patterns, SOLID

  • - Strong knowledge of Android Architecture components

  • - Experience with XMPP, SQL

Q&A to Hire an Android Developer

Finally, we have formed the main requirements. But what if you have several candidates for one vacancy? It's time to prepare technical questions for an interview with your potential developers. Here are some examples of questions that a qualified Android developer with three years of experience will be able to answer:

Question 1. How do you create a borderless button in Android?

Answer: The default android button comes with a border when it is rendered. To remove the border and make it borderless, we can use Shape Drawable. Create a rectangle shape drawable inside your project drawable folder and set the shape drawable to the background property of the Android button.

Question 2. How do you set a transparent background for popup window activity?

Answer: You need to make changes to the translucency settings of your theme in the "AndroidManifest.xml" file and in "styles.xml" file.

Question 3. How to perform callbacks in Android?

Answer: There are multiple ways to approach this answer, but the best way is to use startActivityForResult() to start the activity and then wait for a response. The next step is to query this response into the MainActivity by overriding the onActivityResult() method.

Question 4. Do you think it is necessary to specify Maven in storage while implementing recirculator browsing?

Answer: You should open your ActivityManin.xml file and in pallete option search for recyclerView, click on the download button, and drag and drop it into your screen. It will ask you to add this into import click and it will automatically implement recyclerview dependency into build.gradle file.

Question 5. How can you access the database of an Android app in the Android Studio?

Answer: You can't access any directory on the computer from a mobile application. You should save the data into SQL, JSON, or XML in the res/raw directory and then install to Android SQLite from there.

Question 6. What is the most memory-efficient way to resize bitmaps on Android?

Answer: There are three dominant ways to resize a bitmap on Android which have different memory properties:

- create ScaledBitmap API (this API will take in an existing bitmap, and create a new bitmap with the exact dimensions you’ve selected),

- inSampleSize flag (from a memory perspective, using inSampleSize is a really fast operation. In fact, it will only decode each of the Xth pixels of your image into the resulting bitmap. There are two main issues with inSampleSize though: It doesn’t give you exact resolutions and it doesn’t produce the best quality resize),

- inScaled, inDensity, inTargetDensity flags (If need to scale an image to a dimension that’s not equal to a power of two, then you’ll need the inScaled, inDensity and inTargetDensity flags of BitmapOptions. When inScaled flag has been set, the system will derive the scaling value to apply to your bitmap by dividing the inTargetDensity by the inDensity values).

Question 7. Compare Android online libraries: OkHTTP, and Retrofit.

Answer: Use Retrofit if you need to communicate with a Web service. Use the peer library, Picasso, if you need to download images. Use OkHTTP to do HTTP operations that are impossible to implement using Retrofit. 

Question 8.  How do you force a user to update a live android app?

Answer: The application cannot be confused with updates, all you can do is check which version the user is using at startup, check on your server which version is the latest, and if they are different, ask the user to update.

Question 9. Suppose we need to add the ability for app users to receive notifications that it's time to train.. What's the difference between Instant and LocalDateTime?

Answer: One of the main differences is the local part of LocalDateTime. If you live in Germany and create an instance of LocalDateTime, and someone else lives in the United States and creates another instance at the same time (provided the clock is set correctly), the value of these objects will be different.

Question 10. What is the gap between Expo and React Native?

Answer: Expo is kind of like Rails for React Native. Lots of things are set up for you, so it’s quicker to get started and on the right path. With Expo, you don’t need Android Studio. You should just write JavaScript using whatever text editor you are comfortable with.


Summing Up

Hiring a suitable android developer is challenging, but possible. The main thing is to set the right requirements for the candidate, interview, and select the most suitable developer for your project. We hope the information provided helps you with this request. Good luck with your search!