Java is one of the most commonly used programming languages, which makes a Java developer a huge asset to your team. A 2021 report by Statista states nearly 65% of software developers worldwide use Java as a programming language. With no formal benchmark of qualifications or experience needed to call yourself a Java developer you often end up with a wide pool of candidates at different experience levels.


One disparity we often see with Java developers is a gap around their JVM knowledge. JVM grants applications the "Write once, run anywhere" principle making them platform independent, and while it’s not an essential skill a robust understanding enables developers to write and test high performing code.


Why JVM?

For any job understanding the essentials is key. You might not need to use that knowledge to complete your daily tasks but they provide a solid foundation for you to progress. The same applies to Java developers understanding the heart of Java - the Java Virtual Machine (JVM).


Having a strong grasp on JVM, its parts and how they function helps any developer to write high-performing code and indicates that they take their role, and their development seriously.


It’s tempting to skip the fundamentals and focus on the newer developments. But as a developer it's helpful for you to learn and understand the layer of software below that you’re working at. For instance, if you’re a C++ developer then you should learn assembly language to understand what the compiler is generating for you. For Java developers, that level is JVM.


Historically, JVM only supported Java. Over time other languages such as Scala, Kotlin and Groovy has been incorporated into the Java platform. Fundamentally, a deep understanding of JVM will enable you to write better code while avoiding pitfalls relating to stack and memory errors.


Assessing JVM Skills

It’s not essential to understand JVM as a developer but a solid understanding marks that individual out as a cut above the rest, not only in their rounded technical know-how but also in their desire to develop themselves and their knowledge. 


Without an understanding of an individual’s current JVM skill level it’s challenging to establish their gaps in knowledge. Their current competency could be assessed via a proficiency test or through a conversation with a Java developer well versed in JVM, asking questions related to Just-in-Time compilation, multithreading, JVM options, class loading, concurrency handling, compile-time and runtime errors. 


Once their existing level of competency has been established you can then develop a plan to increase their understanding of JVM.

Learning JVM


The best methods for learning about JVM and bridging the skills gap is through independent learning. There are many courses out there that cover aspects of JVM in more depth including:


● Oracle university

● Udemy

● Great Learning

● Data Flair Training

● Pluralsight


It’s best to identify the specific area of learning you want to focus on then find a course that supports you to do just that.


Alternatively, online resources and books like “The Definitve Guide to Java Performance” by Scott Oaks, which covers JVM in-depth. If you’re someone who prefers to take a hands-on approach they may help you learn through doing. 


The future of JVM

JVM now incorporates possibly the biggest collection of languages of any bytecode making it still a crucial part of development connecting older and younger generations of coding languages. It’s not going anywhere in the near future and that’s why it’s still an essential skill for any serious developers. 


JVM is an essential, but often overlooked skill for developers to have. For developers it can be tempting to focus on newer developments without fully understanding the basic building blocks. Overcoming this requires either a change in recruitment processes to fully evaluate a candidate’s competency or a commitment by that candidate to dedicate time to upskilling their knowledge. This is something an employer can support through training courses, dedicated learning time or working with experienced colleagues to learn on the job. 


With a wealth of courses and learning available online, a supportive employer and a keen developer then overcoming any skills gaps in JVM should be relatively straightforward.  


If you need advice on your job search, contact the Source Technology team today. Our recruitment consultants are on hand to help you discover your dream role. hello@source-technology.com