Home
/
Blog
/
Developer Insights
/
How to assess a Java developer skills while hiring

How to assess a Java developer skills while hiring

Author
Arpit Mishra
Calendar Icon
May 22, 2017
Timer Icon
3 min read
Share

Java has continued to be a major force in enabling these technologies within these enterprises.

The problem arises when you want to hire a candidate who has proven Java developer skills.

How do you assess Java developer skills with accuracy when you have no clue how Java works or have never worked init?

If you want to hire a developer who knows Java but doesn’t know how to develop good quality code in a reasonable amount of time, then proceed with the Java APIs and programming tests.

If you want a decent developer, then forget about a paper-pen programming assessment and just talk to them about how they would go about building solutions and the tools they would use, and you’d better use an online assessment.

Ask them about frameworks they know of and what their strengths and weaknesses are as developers. (Read:How to hire a technical source)

Awareness of different IDEs, build tools, test tools, and documentation skills would also be worth querying. If you want quality software, it’s important that they know the “why” and the “how.”

Does a resume by itself represent the actual skills of a candidate? If not, then how can you screen the candidate?

I’ve seen people without degrees who could write incredible algorithms and could quote Knuth by heart.

How can you find the right Java developer skills for your organization?

In this post, I will discuss the best practices we follow while hiring and screening Java developersat HackerEarth.

But before I begin, here’s a little primer.

Why Java?

Java is the closest thing to a Lingua Franca (idiom meaning “Common Language”) in the IT industry. Everyone who has used it once is likely to stick with it.

Java is a computing platform used for portable codes for desktop and server environments. In simple terms, it helps develop an application and share it cross-platform.

It’s an object-oriented programming language which comes with the niche facility of a just-in-time compiler.

What do you need to know before you hire a Java Developer?

Since Java is so often used in every possible application in IT, it is essential to understand that learning it in college or getting basic certifications are hardly useful unless the recruitment is for a beginner’srole.

Java is changing almost every year and with new build and framework releases, hands-on experience in the latest or required libraries and framework should be the priority.

These libraries contain pre-written essential required functions; you can save time by not having to rewrite anything.

A candidate working on J2SE 5.0 released in 2004 may not be knowledgeableenoughto work in Java 8 released in 2014.

Before we begin discussing the Java developer online hiring process, it is essential to understand common terms used in Java hiring. Many of these terms are often used interchangeably, and I will be sharing only the important ones.

Check out this amazing glossary of all the Java terms here .

What is Java SE and Java EE?

It refers to Java Standard Edition used for development and deployment of codes for the desktop environment.

Java Enterprise Edition is built on top of Java SE. Java EE provides an API and runtime environment for developing and running a large-scale application.

What certification can you expect?

Most candidates today, who see themselves as skilled developers, are certified in Java. But what are the various Java certifications and what do they mean?

Oracle has 4 levels of Java certification that certify you in different levels of expertise.

The table below represents the four levels and the certification and associated skills.

Oracle Certified Associate (OCA) Oracle certified Associate, Junior Java SE 5,6,8 Fundamental skills
Oracle Certified Professional (OCP) Oracle certified Associate, OCAJP 7, OCAJP 8 Implementation, Basic of web development
Oracle Certified Expert (OCE) OCPJP 6, OCPJP 7, OCPJP 8 Web Development, API, Enterprise, Server Faces, Web Services
Oracle Certified Master (OCM) OCEJWCD 6, OCEJWSD 6, OCEJSFD 6, OCEEJBD 6, OCEJPAD Architect, Designing, Enterprise edition technology

* Only Oracle certified candidates are considered to be Java certified.

List of common skills on which candidates are evaluated in a Java Developer hiring process

  • OOP Concepts
    • Abstraction (Interface, Abstract Class, implements)
    • Encapsulation (access modifiers – public, private, protected, default)
    • Inheritance (extends, super)
    • Polymorphism (overloading, overriding)
  • Core Java Concepts
    • Variables, Scope of Variables, Autoboxing/Unboxing, Constructors, Operators, Input, Output, Conditions, Loops, Methods, Arrays, Objects, String APIs)
  • Advanced Concepts
    • Packages, Interfaces, Inheritance, Polymorphism, Exceptions
  • Java Generics
  • Collections/Data Structures
    • Lists, Maps, Arrays Lists, Sets
  • Inner Classes
  • Static – Keywords
  • File Handling APIs
  • Network APIs
  • Garbage Collection
  • Serialization
  • JVM Architecture
  • Frameworks
    • Spring, Hibernate
  • Multi-Threading
    • (Synchronization, Thread, Runnable)
  • Experience in web services (REST and/or SOAP)
  • Build tools – e.g. Ant, Maven
  • Lambda Expressions
  • Streams
  • J2EE, EJB, JSF

Irrespective of this detailed list, there is no definite fail-safe way or approach to judging a candidate on these parameters.

Assessing a Java developer skills

Screening is often considered tedious, time-consuming, and still frequently inefficient when you are trying to find the right candidate. You may source 500 or 1000 resumes for a job, but what is important is getting the most suitable candidate for the job.

Over a period, I’ve realized that any Java developer candidate can be screened based on the following two challenges:

  • Simple algorithmic challenge
  • Application development

Simple Algorithmic Challenge

Despite some really amazing sources available for more detailed testing, many firms still prefer using simple algorithmic challenges in assessing the job aspirants. (Read – How to remotely assess tech talent?)

Thecandidate is provided with one or many programming problems which have to be completed within the stipulated time. The solutions are usually judged based on test cases, time, and memory efficiency.

Each programming challenge taken by candidates is evaluated for its accurateness, time, and space complexity by the technical team.

Unlike automated scoring, human raters could bias test results in different ways.

Tools like HackerEarth – Recruit help you test candidates with minimumhuman intervention. (5 reasons you should use a talent assessment tool)

Recruit challenges candidates using questions from its extensive library while also providing flexibility to enter questions of the recruiter’s choice.

A candidate can be tested on various programming skills through multiple-choice questions, subjective questions, programming questions, golf questions (Problems which are solved in the least number of steps), and approximation questions.

The solution to these questions is automatically evaluated based on defined criteria.

A sample Golf problemstatement for assessment:

How to hire Java developers, Assess java developers, Hire a Java programmer, how to assess java programmer, How to assess senior java developer, best ways to hire a programmer, Assessment tools for Java developers, Assessment tools, HR tools for Java developers, how do i hire Java Developers, hire a java developer, java developer skills

Application Development – Java Multiple File Project Challenges

Real-life problems do not come with a problem statement. Developers usually deal with problems of finding the right framework or editing a broken patch in a program while coding.

When it comes to hiring senior-level or experienced Java developers, it becomes verydifficult for recruiters, as well as candidates, to demonstrate their knowledge and skill througha simple programming challenge.

A full-fledged application challenge is used to test a candidate’s capability of developing a complete Java application. He or she has to apply theoretical knowledge and practical skills to get a complete application running.

The candidate must know enough about the framework and libraries to survive the screen test. The solution is then assessed manually using JUnit and by creating custom test cases.

HackerEarth Java Multi File Application helps you assess candidates on application-building skills. Similar to Algorithmic challenges, you can test candidates by using questions from the Recruit library or via a custom library.

The application feature helps a recruiter to check candidates’ know-how by requesting them to develop an application from scratch.

Or the recruiter can choose to partially share an application feature and ask them to complete the rest as part of the assessment.

Benefits of using a Java Multifile Project are the following:

  • It can be used to test hands-on programming skills rather than just algorithmic coding knowledge.
  • Candidates can actually relate the problems to real-life scenarios, which makes problem-solving interesting.
  • JUnits help in testing the entire code flow and not just I/O. Output matching is flawed and can even be achieved through brute force. JUnits on the other hand, if written properly, can test the entire code flow of the candidate.

How to hire Java developers, Assess java developers, Hire a Java programmer, how to assess java programmer, How to assess senior java developer, best ways to hire a programmer, Assessment tools for Java developers, Assessment tools, HR tools for Java developers, how do i hire Java Developers, hire a java developer, hire a java developer, java developer skills

You may have realized while reading this lengthy article that the best approach to assess a Java developer is not via conventional approaches but vianew technologies foreffective assessment.


Popular posts like this:
  1. How to hire a data scientist
  2. 5 must-have proctoring tips for a developer assessment platform
  3. How to ensure your tech talent pool is poaching proof

Subscribe to The HackerEarth Blog

Get expert tips, hacks, and how-tos from the world of tech recruiting to stay on top of your hiring!

Author
Arpit Mishra
Calendar Icon
May 22, 2017
Timer Icon
3 min read
Share

Hire top tech talent with our recruitment platform

Access Free Demo
Related reads

Discover more articles

Gain insights to optimize your developer recruitment process.

The Mobile Dev Hiring Landscape Just Changed

Revolutionizing Mobile Talent Hiring: The HackerEarth Advantage

The demand for mobile applications is exploding, but finding and verifying developers with proven, real-world skills is more difficult than ever. Traditional assessment methods often fall short, failing to replicate the complexities of modern mobile development.

Introducing a New Era in Mobile Assessment

At HackerEarth, we're closing this critical gap with two groundbreaking features, seamlessly integrated into our Full Stack IDE:

Article content

Now, assess mobile developers in their true native environment. Our enhanced Full Stack questions now offer full support for both Java and Kotlin, the core languages powering the Android ecosystem. This allows you to evaluate candidates on authentic, real-world app development skills, moving beyond theoretical knowledge to practical application.

Article content

Say goodbye to setup drama and tool-switching. Candidates can now build, test, and debug Android and React Native applications directly within the browser-based IDE. This seamless, in-browser experience provides a true-to-life evaluation, saving valuable time for both candidates and your hiring team.

Assess the Skills That Truly Matter

With native Android support, your assessments can now delve into a candidate's ability to write clean, efficient, and functional code in the languages professional developers use daily. Kotlin's rapid adoption makes proficiency in it a key indicator of a forward-thinking candidate ready for modern mobile development.

Breakup of Mobile development skills ~95% of mobile app dev happens through Java and Kotlin
This chart illustrates the importance of assessing proficiency in both modern (Kotlin) and established (Java) codebases.

Streamlining Your Assessment Workflow

The integrated mobile emulator fundamentally transforms the assessment process. By eliminating the friction of fragmented toolchains and complex local setups, we enable a faster, more effective evaluation and a superior candidate experience.

Old Fragmented Way vs. The New, Integrated Way
Visualize the stark difference: Our streamlined workflow removes technical hurdles, allowing candidates to focus purely on demonstrating their coding and problem-solving abilities.

Quantifiable Impact on Hiring Success

A seamless and authentic assessment environment isn't just a convenience, it's a powerful catalyst for efficiency and better hiring outcomes. By removing technical barriers, candidates can focus entirely on demonstrating their skills, leading to faster submissions and higher-quality signals for your recruiters and hiring managers.

A Better Experience for Everyone

Our new features are meticulously designed to benefit the entire hiring ecosystem:

For Recruiters & Hiring Managers:

  • Accurately assess real-world development skills.
  • Gain deeper insights into candidate proficiency.
  • Hire with greater confidence and speed.
  • Reduce candidate drop-off from technical friction.

For Candidates:

  • Enjoy a seamless, efficient assessment experience.
  • No need to switch between different tools or manage complex setups.
  • Focus purely on showcasing skills, not environment configurations.
  • Work in a powerful, professional-grade IDE.

Unlock a New Era of Mobile Talent Assessment

Stop guessing and start hiring the best mobile developers with confidence. Explore how HackerEarth can transform your tech recruiting.

Vibe Coding: Shaping the Future of Software

A New Era of Code

Vibe coding is a new method of using natural language prompts and AI tools to generate code. I have seen firsthand that this change makes software more accessible to everyone. In the past, being able to produce functional code was a strong advantage for developers. Today, when code is produced quickly through AI, the true value lies in designing, refining, and optimizing systems. Our role now goes beyond writing code; we must also ensure that our systems remain efficient and reliable.

From Machine Language to Natural Language

I recall the early days when every line of code was written manually. We progressed from machine language to high-level programming, and now we are beginning to interact with our tools using natural language. This development does not only increase speed but also changes how we approach problem solving. Product managers can now create working demos in hours instead of weeks, and founders have a clearer way of pitching their ideas with functional prototypes. It is important for us to rethink our role as developers and focus on architecture and system design rather than simply on typing c

The Promise and the Pitfalls

I have experienced both sides of vibe coding. In cases where the goal was to build a quick prototype or a simple internal tool, AI-generated code provided impressive results. Teams have been able to test new ideas and validate concepts much faster. However, when it comes to more complex systems that require careful planning and attention to detail, the output from AI can be problematic. I have seen situations where AI produces large volumes of code that become difficult to manage without significant human intervention.

AI-powered coding tools like GitHub Copilot and AWS’s Q Developer have demonstrated significant productivity gains. For instance, at the National Australia Bank, it’s reported that half of the production code is generated by Q Developer, allowing developers to focus on higher-level problem-solving . Similarly, platforms like Lovable enable non-coders to build viable tech businesses using natural language prompts, contributing to a shift where AI-generated code reduces the need for large engineering teams. However, there are challenges. AI-generated code can sometimes be verbose or lack the architectural discipline required for complex systems. While AI can rapidly produce prototypes or simple utilities, building large-scale systems still necessitates experienced engineers to refine and optimize the code.​

The Economic Impact

The democratization of code generation is altering the economic landscape of software development. As AI tools become more prevalent, the value of average coding skills may diminish, potentially affecting salaries for entry-level positions. Conversely, developers who excel in system design, architecture, and optimization are likely to see increased demand and compensation.​
Seizing the Opportunity

Vibe coding is most beneficial in areas such as rapid prototyping and building simple applications or internal tools. It frees up valuable time that we can then invest in higher-level tasks such as system architecture, security, and user experience. When used in the right context, AI becomes a helpful partner that accelerates the development process without replacing the need for skilled engineers.

This is revolutionizing our craft, much like the shift from machine language to assembly to high-level languages did in the past. AI can churn out code at lightning speed, but remember, “Any fool can write code that a computer can understand. Good programmers write code that humans can understand.” Use AI for rapid prototyping, but it’s your expertise that transforms raw output into robust, scalable software. By honing our skills in design and architecture, we ensure our work remains impactful and enduring. Let’s continue to learn, adapt, and build software that stands the test of time.​

Ready to streamline your recruitment process? Get a free demo to explore cutting-edge solutions and resources for your hiring needs.

Guide to Conducting Successful System Design Interviews in 2025

What is Systems Design?

Systems Design is an all encompassing term which encapsulates both frontend and backend components harmonized to define the overall architecture of a product.

Designing robust and scalable systems requires a deep understanding of application, architecture and their underlying components like networks, data, interfaces and modules.

Systems Design, in its essence, is a blueprint of how software and applications should work to meet specific goals. The multi-dimensional nature of this discipline makes it open-ended – as there is no single one-size-fits-all solution to a system design problem.

What is a System Design Interview?

Conducting a System Design interview requires recruiters to take an unconventional approach and look beyond right or wrong answers. Recruiters should aim for evaluating a candidate’s ‘systemic thinking’ skills across three key aspects:

How they navigate technical complexity and navigate uncertainty
How they meet expectations of scale, security and speed
How they focus on the bigger picture without losing sight of details

This assessment of the end-to-end thought process and a holistic approach to problem-solving is what the interview should focus on.

What are some common topics for a System Design Interview

System design interview questions are free-form and exploratory in nature where there is no right or best answer to a specific problem statement. Here are some common questions:

How would you approach the design of a social media app or video app?

What are some ways to design a search engine or a ticketing system?

How would you design an API for a payment gateway?

What are some trade-offs and constraints you will consider while designing systems?

What is your rationale for taking a particular approach to problem solving?

Usually, interviewers base the questions depending on the organization, its goals, key competitors and a candidate’s experience level.

For senior roles, the questions tend to focus on assessing the computational thinking, decision making and reasoning ability of a candidate. For entry level job interviews, the questions are designed to test the hard skills required for building a system architecture.

The Difference between a System Design Interview and a Coding Interview

If a coding interview is like a map that takes you from point A to Z – a systems design interview is like a compass which gives you a sense of the right direction.

Here are three key difference between the two:

Coding challenges follow a linear interviewing experience i.e. candidates are given a problem and interaction with recruiters is limited. System design interviews are more lateral and conversational, requiring active participation from interviewers.

Coding interviews or challenges focus on evaluating the technical acumen of a candidate whereas systems design interviews are oriented to assess problem solving and interpersonal skills.

Coding interviews are based on a right/wrong approach with ideal answers to problem statements while a systems design interview focuses on assessing the thought process and the ability to reason from first principles.

How to Conduct an Effective System Design Interview

One common mistake recruiters make is that they approach a system design interview with the expectations and preparation of a typical coding interview.
Here is a four step framework technical recruiters can follow to ensure a seamless and productive interview experience:

Step 1: Understand the subject at hand

  • Develop an understanding of basics of system design and architecture
  • Familiarize yourself with commonly asked systems design interview questions
  • Read about system design case studies for popular applications
  • Structure the questions and problems by increasing magnitude of difficulty

Step 2: Prepare for the interview

  • Plan the extent of the topics and scope of discussion in advance
  • Clearly define the evaluation criteria and communicate expectations
  • Quantify constraints, inputs, boundaries and assumptions
  • Establish the broader context and a detailed scope of the exercise

Step 3: Stay actively involved

  • Ask follow-up questions to challenge a solution
  • Probe candidates to gauge real-time logical reasoning skills
  • Make it a conversation and take notes of important pointers and outcomes
  • Guide candidates with hints and suggestions to steer them in the right direction

Step 4: Be a collaborator

  • Encourage candidates to explore and consider alternative solutions
  • Work with the candidate to drill the problem into smaller tasks
  • Provide context and supporting details to help candidates stay on track
  • Ask follow-up questions to learn about the candidate’s experience

Technical recruiters and hiring managers should aim for providing an environment of positive reinforcement, actionable feedback and encouragement to candidates.

Evaluation Rubric for Candidates

Facilitate Successful System Design Interview Experiences with FaceCode

FaceCode, HackerEarth’s intuitive and secure platform, empowers recruiters to conduct system design interviews in a live coding environment with HD video chat.

FaceCode comes with an interactive diagram board which makes it easier for interviewers to assess the design thinking skills and conduct communication assessments using a built-in library of diagram based questions.

With FaceCode, you can combine your feedback points with AI-powered insights to generate accurate, data-driven assessment reports in a breeze. Plus, you can access interview recordings and transcripts anytime to recall and trace back the interview experience.

Learn how FaceCode can help you conduct system design interviews and boost your hiring efficiency.

Top Products

Explore HackerEarth’s top products for Hiring & Innovation

Discover powerful tools designed to streamline hiring, assess talent efficiently, and run seamless hackathons. Explore HackerEarth’s top products that help businesses innovate and grow.
Frame
Hackathons
Engage global developers through innovation
Arrow
Frame 2
Assessments
AI-driven advanced coding assessments
Arrow
Frame 3
FaceCode
Real-time code editor for effective coding interviews
Arrow
Frame 4
L & D
Tailored learning paths for continuous assessments
Arrow
Get A Free Demo