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Lucy Oleschuk
Level 31

Top Skills and Main Responsibilities of Junior Java Developers

Published in the Random group
When it comes to the IT industry, you probably already heard that there are three main levels of developers — Juniors, Middles, and Seniors. Today, we’re going to explore the “greenest” of them, Junior Java developers, and shed light on your prospects, duties, and skills. Top Skills and Main Responsibilities of Junior Java Developers - 1

Who Is a Junior Java Developer?

To start with the basics, let's paint a clear portrait of a Junior Java developer. A Junior Java developer is a fresh specialist who is just entering the world of programming. Frankly speaking, there is a noticeable difference between a Junior and a Middle dev. The main distinction is that juniors are “just-graduated” coders who need to learn many new things, whereas Middles already have 2-4 years of experience behind their belts and can work alone, with no supervision. That is to say, Junior developers typically work on all stages of the development projects at the beginning of their career to gain experience. And if you’re wondering what Junior Developers' main responsibilities are, here is a brief review. As a Junior Java developer, you should:
  • have up to 1.5 years of “learning” experience with an intrinsic passion for improving your skills;
  • understand how software interacts with hardware;
  • know Java syntax, collections, and multithreading;
  • know how to manage interfaces, classes, and objects;
  • know basic OOP principles;
  • be able to write and maintain the code;
  • work with essential tools for coding like IntelliJ IDEA
  • work with version-control systems and services like GitHub or/and GitLab;
  • know object-relational mapping (Hibernate);
  • know the frameworks for creating web-oriented projects like Spring or Spring Boot;
  • work on the admin side of these tools/features;
  • be able to fix minor bugs and mistakes in code;
  • work with tools for unit testing (JUnit, Mockito);
  • have a basic knowledge of JavaScript and HTML5/CSS3;
  • want to learn new software platforms, different project structures, and technologies;
  • have the ability to follow instructions set by Senior software developers and work in a team;
  • prepare reports, instructions, and other documentation for the project planning process;
  • gather information from users about the products.
So, this list makes it evident that a Junior Java specialist is involved in all project stages, from brainstorming to testing. Also, besides having solid computer knowledge, you should be a good team player and have good communication skills to interact with your peers and clients.

Essential Skillset for Junior Java Developers

Well, what do we mean by solid Java knowledge? As mentioned, Junior Java developers' responsibilities are really broad, so your skillset should be rich too. Among others, besides Core Java knowledge, you’ll need to acquire the following skills:
  • JavaServer pages (JSP) and servlets
  • Web frameworks (Spring)
  • Web technologies (HTML, CSS, JavaScript, and JQuery)
  • Service-oriented architecture/web services (SOAP/REST)
  • Object-oriented programming (OOP) concepts and patterns
  • Markup languages (XML and JSON)
  • Abstract classes and interfaces
  • Constructors, Collections, Exceptions (checked and unchecked)
  • File IO and serialization
  • Access specifiers
  • Multithreading and synchronization
  • Generics
  • Java virtual machine (JVM) and memory management
  • Dependency injection
That just being said, the skillset for Android Junior Developers is a little narrower and includes:
  • XML
  • Android SDK
  • Android Studio
  • APIs
  • Databases
  • Material Design
As for QA Automation Juniors, they should be proficient in:
  • Fundamentals of QA methodology
  • Framework design
  • Patterns used in automation (Page Object, Factory)
  • Experience in CI and CD
  • Knowledge of Maven, Selenoid, JUnit, and similar tools

The Main Obstacles on Your Way and Possible Solutions

After you define your goals and acquire the knowledge essential for your future career, it is not the moment of the dream. Fresh graduates may still face some issues on the way to their dream jobs:

Poor English

Even if you have impressive coding skills, you may get stuck simply because you struggle with English. The thing is, the majority of large IT companies require at least a basic level of English to hold interviews, communicate with employers and customers, as well as make sure you get the tasks right. So, if you have an intermediate level of English at least, this will definitely speed up your job search and boost your career in the future.

Too Much Java

Don’t overburden yourself with learning too much Java. Java is a pretty complex language with its syntax, databases, frameworks, patterns, algorithms, etc. So, many students struggle with switching from learning to job hunting. You can’t know everything, but you can learn more while actually working on real projects. Keep in mind that there will never be enough Java, so try to send out your CVs as soon as you feel ready to enter a real project (and earn real money).

Project-less Portfolio

Of course, companies prefer candidates with some experience as they value the proven track record of development projects. Frankly speaking, it may be the primary recruitment criterion for most employers. Hopefully, our Games section allows you to create your own games. Use our intuitive engine and follow step-by-step instructions to write your first programs. If you'd like to have the real project in your GitHub, then you should consider joining CodeGym's mentorship course on Java Fundamentals. It includes online lectures with a mentor, a detailed training program with tons of tasks and additional materials, and writing the final project (straight for your GitHub portfolio) at the end of your learning. The bonus: the mentor will review your project and give you individual feedback and hints for improvement, so you can later show a flawless project to your future employers. Yet, if you still have no projects to boast of, you can mention in your CV that you’d be happy to complete a test task for the company. A win-win decision for both parties.


When you finally get an invitation to your first job interview, you can expect standard and tricky questions. So, it's makes sense to surf the Net beforehand to get prepared for the most daunting of them. When interviewing a developer without experience, the employers will most likely focus on your Java knowledge and problem-solving skills. Also, they will estimate your willingness to learn new things, your communicative skills, and your “team spirit”. Don't fear to fail during your first interviews, it’s quite OK to land your first job after a dozen of them. Just analyze each of your interviews to improve and get closer to your dream step by step. Also, keep yourself motivated and passionate about your future career. You definitely deserve your place in the sun!