Last Updated: August 17, 2023


Rohit Rawat


Hiring the right candidate for a job is an important part of any development project. Java might be the most popular programming language, but it also comes with a drawback. Due to its popularity, many budding developers learn it in the hope of landing a job. Therefore, you will have an enormous list of candidates. Hence, finding the one with the best Java developer skills becomes a difficult task.

Therefore, we have designed this article in such a way that it will also become easy for you to vet the best developer. Ranging from fresher to intermediate to expert, this list has a few basic questions that every Java developer must know.

Questions to Ask a Fresher Java Developer

To hire the right candidate, you need to ask questions based on their skill level. This section contains questions you should ask a beginner Java developer.

What are the features of Java?

1.  Platform Independent

Unlike many other programming languages, such as C and C++, Java is converted into platform-independent bytecode rather than platform-specific machine code. This byte code is also delivered over the internet, and the Virtual Machine (JVM) interprets it on the platform on which it is executed.

2. Easy to Learn

The makers of Java intended it to be simple to learn. Furthermore, It is simple to grasp OOP Java if you understand the fundamental concepts

3. Secure

The security feature of Java makes it possible to create a fool-proof system. Besides, It utilizes public-key encryption in authentication systems which also gives a boost to its security.

4. Architecturally Neutral

With the inclusion of the Java runtime system, the Java compiler creates an architecture-neutral object file format. That makes the produced code executable on a wide range of processors.

5. Portable

The neutral architecture, as well as independent features of Java, make it highly portable. The Java compiler is developed in ANSI C, which is a POSIX subset with a clear portability feature.

What is a ClassLoader in Java?

The Java ClassLoader is a part of the Java Runtime Environment that loads Java classes into the Java Virtual Machine. Also, there is no need for the Java runtime system to know about files or file systems due to the presence of classloaders.

Java classes are loaded into memory as needed by an application and not at once. The JRE calls the Java ClassLoader, as a result these ClassLoaders dynamically load classes into memory. Make sure your Java application development services provider is aware of its benefits.

The main difference between Heap memory and Stack memory in Java?

Memory management is a crucial operation in Java, and it takes care of it automatically. The JVM divides memory into two sections: stack memory and heap memory. From a Java point of view, both are important memory locations, but the system uses them for different things.

The main difference between stack memory and heap memory is that stack memory keeps track of the order in which methods are run and local variables, whereas heap memory stores objects and employs dynamic memory allocation as well as deallocation.

You can judge the skills of a Java developer based on how they answer this question.

Ask About Aggregation in Java

It is a connection between two classes in Java that is best defined as "has-a" and "whole/part." It's a subset of the associated connection. The aggregate class has ownership of another class since it has a reference to it. Therefore, we can consider each referenced class as a component of the aggregate class.


Questions for Intermediate Java Developer

Do you want a more experienced Java developer for your project? Make sure you ask them these questions.

Ask About JDK (Java Development Kit)

It is a software development environment that works on multiple platforms. It has a set of tools and libraries for making Java-based apps. Along with the JVM (Java Virtual Machine) and the JRE (Java Runtime Environment), it is a key package in Java (Java Runtime Environment).

Also, it is the most important aspect of Java development that every major Java web application development company uses.

What exactly are the distinctions between JDK, JRE, and JVM?

  • JDK stands for Java Development Kit, whereas JRE is a software package that allows Java programs to run, and JVM is for Java Virtual Machine.
  • JRE and JDK are platform-dependent, but JVM is not.
  • JDK includes tools for programming, debugging, as well as other tasks. JRE includes class libraries and other supporting files. JVM does not include software development tools.
  • JDK includes the installer, whilst JRE just includes the environment for running source code. Both JDK and JRE include JVM.

What is a JIT (Just-In-Time) Compiler in Java?

It is a critical component of JRE. It is responsible for optimizing the performance of Java-based applications at runtime. The compiler is one of the most important factors in determining an application's performance for both the user as well as the developer.

JIT compilers interact with the Java Virtual Machine (JVM) at run time to convert appropriate bytecode sequences into native machine code, which improves performance. Instead of the JVM interpreting the same sequence of bytecode again and incurring overhead for the translation process, a JIT compiler allows the hardware to run native code.

This results in performance benefits in execution speed but the developers of your Java software development services provider shouldn't run the compiled methods frequently.

Questions to Ask Expert Java Developers

To lead the entire project, the person needs to be an expert in the language. Ask the questions mentioned in this section to hire an expert Java developer.

Ask About JDBC (Java Database Connectivity)

It is a Java API for connecting to and querying databases. It's included in JavaSE (Java Standard Edition). If the JDBC API wants to connect to the database, it utilizes JDBC drivers. Additionally, developers can use the JDBC API to access tabular data in any relational database. They can store, update, remove, and get data from the database using the JDBC API.

Do They Know About JSP and its directives?

Developers use JSP (Java Server Pages) technology to develop web applications. We can consider it a Servlet extension because it has more features than Servlet, like expression language and JSTL.

A JSP page is made up of HTML and JSP tags. Since we can separate design and development, JSP pages are easier to maintain than Servlets. It also has certain features, such as Expression Language and Custom Tags.

JSP directives are parts of the JSP source code that tell the web container how to convert the JSP page into its servlet counterpart. A directive can have several attributes, which developers can define as key-value pairs separated by commas. The space between the @ symbol and the directive name and between the last attribute and the closing percent >, is optional. The Java website development agency that you hire must use this feature to capitalize on its benefits.

There are three types of JSP directives-

  • Page Directive
  • Include Directive
  • Taglib Directive

Ask About Session Management in Java

It is a Java technique for storing session information in Web containers. A way of managing a user's data is session tracking. It is also known as session management in servlet. Developers can use other methods like HTTP Session API, Cookies, URL rewriting, and other methods to manage sessions in Java.

Many Java website development services use it to allow the server of the website to remember its visitors. A session is a communication between a server and a client that consists of a sequence of uninterrupted requests and answers.

Explain the Spring Framework.

The Spring framework is an open-source Java platform that provides complete infrastructure support for quickly developing strong Java applications. Therefore, when it comes to size and transparency, Spring is very light and transparent. Its basic version is about 2MB in size.

Developers can use the fundamental capabilities of the Spring framework in any Java program. However, there are modifications for building web applications on the Java EE platform. By offering a POJO-based programming model, the Spring framework aims to make J2EE software easier to use. You must hire Java developers who are well-versed in using this framework.



Ensuring that the developers you hire are adequately skilled is an action that will make or break your Java project. And to do that, it is essential that you ask the right questions. But wouldn’t it be wonderful if you could find developers who are already vetted and ready for action?

Narola Infotech is a Java development company that conducts rigorous interviews and recruitment exercises to hire developers. As a result, it filters out many candidates but the ones who are left are the cream. No doubt, your project will take a turn towards success if you hire our developers. Feel free to contact us any time to discuss your project requirement and how we can take it forward.

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