The Java language is more than 30 years old, and yet it remains in strong demand by organizations of all sizes. Java is a staple in decades’ worth of legacy codebases, and companies everywhere still use it every day to build new apps and services. As a result, those who’ve mastered the intricacies of Java can have their pick of potential engineering and development roles.
Although Java is (arguably) most famously used in Android, Google’s mobile operating system, it’s also a key element in everything from enterprise applications to machine learning to Internet of Things (IoT) to gaming. Depending on the company and position, a Java engineer might work on everything from creating and updating services to creating new apps and modernizing codebases.
What Does a Java Engineer Do?
In broadest terms, a Java engineer is responsible for developing and maintaining Java-based software applications across various industries and often for multiple platforms. The duties of a Java engineer will vary depending on the size and type of the organization they work for, but typical duties involve:
- Analyzing user requirements and translating them into technical specifications.
- Developing data scraping programs.
- Development and support of Java-based software applications.
- Writing code (Java and other languages as needed).
- Testing and debugging code.
- Troubleshooting and resolving issues.
- Maintaining codebases.
- Updating standard libraries.
For Java developers and engineers who end up leading teams, there are also the responsibilities associated with management, such as communication and empathy—“soft skills” that matter just as much as technical skills in many scenarios.
What Skills Do Java Engineers Need?
Java engineers need a wide range of skills to be successful in their careers, including:
Java programming skills: Java engineers must be able to write code that is understandable to others. Engineers must also be familiar with Java's syntax, libraries, and frameworks. If you’re just starting out on your Java journey, there are lots of tutorials and documentation online for learning. For example, the Java Developer Kit (JDK) has lots of built-in support and documentation, including extensive breakdowns of its libraries. If you’re a visual learner, Microsoft also has a website featuring a series of short videos dedicated to the fundamentals of Java.
Object Oriented Programming (OOP): OOP is a fundamental concept in Java programming. Java engineers need to be able to design and implement object-oriented software. They must also be familiar with the different OOP concepts, such as classes, objects, inheritance, and polymorphism. If you’re curious about how OOP intersects with Java, check out this extensive tutorial on w3schools.
Knowledge of software design and development principles: Java engineers need to be able to design and develop well-designed, scalable, and maintainable software. That means knowing different development principles (such as the Model-View-Controller (MVC) pattern and the Singleton pattern). Bootcamps and online learning courses will teach much of this, as will a traditional two- or four-year program in software development.
Ability to write clear and concise code: Java engineers need to be able to write code that is easy to read, understand, and maintain. They also need to be able to document their code so that other developers can understand it. If coding is frustrating for you, take heart: everyone starts somewhere, and it can take quite a bit of time for a software developer or engineer to truly master the writing of elegant code.
Debugging and troubleshooting: Java engineers need to be able to identify the source of code-based problems and find practical solutions.
Ability to work independently and as part of a team: Java engineers often work on projects as part of a team. They must work effectively with other developers and communicate effectively with their team members. As with technical skills, these “soft skills” take time to develop, so don’t be frustrated if you have some setbacks early in your Java developer career; you’ll become an effective team member in no time.
Excellent problem-solving skills: Java engineers need to be able to solve problems creatively and efficiently. They need to be able to identify the root cause of a problem and develop a solution that is both effective and efficient. Fortunately, problem solving is a skill that you can improve with some critical thinking and effort.
Attention to detail. Java engineers need to be able to pay attention to detail; this helps on a line-by-line basis with writing code, and also when efficiently troubleshooting issues.
What Does a Java Engineer Make Annually?
Java engineers in the United States make $126,100 per year, on average, as of July 2023, according to data from Indeed, ZipRecruiter, and Salary.com.
Remember that the salary for Java engineers can vary greatly depending on experience, location, and the industry they are working in. Java engineers in the San Francisco Bay Area can expect to earn an average annual salary of about $150,000. A Java engineer with 10 years of experience in New York City can expect about $175,000 per year.
Similarly, Java engineers in the finance or healthcare industries earn more than those in government or retail.
According to Bureau of Labor Statistics (BLS) data, the demand for Java engineers is projected to grow 22 percent by 2030, faster than average.
Which Programming Languages Should Java Engineers Learn?
Naturally, it all starts with Java (that’s why you’re reading this article, right?). “Java is the foundation of a Java engineer's skill set,” says Ben Landman, senior software engineer at Sovtech. “With its ‘write once, run anywhere’ philosophy and widespread usage in enterprise applications, Android app development, and backend systems, Java is a fundamental language for Java engineers.”
Konstantin Glumov, software engineer at Alfa-Bank, adds: “When developing large modern web applications, it is sometimes not enough for Java engineers to know only one language. There are often tasks that require knowledge of additional languages.”
Kotlin is a great language for Java devs to learn, Glumov adds: “It is fully compatible with the Java ecosystem because it uses JVM under the hood. Many novice and experienced developers recognize its convenience and conciseness before Java and start using it as the main one. If you are developing an application in a microservice architecture, you can develop different applications in both languages using the same frameworks and libraries.”
Google declared Kotlin a “first class language” for Android development, raising the language’s profile substantially. It’s regularly listed as one of the most-loved languages on Stack Overflow’s annual Developer Survey, and makes notable appearances on HackerRank’s annual Developer Skills Report. Developers enjoy using it in the context of Java applications, in other words, and it’s well worth checking out if you’ve never heard of it.
“Developers on some projects combine writing a backend and a frontend. In this case, knowledge of JavaScript (and its older brother TypeScript) will help your work,” Glumov continues. “This language is the main one for writing the client side of web applications. But even if you do not work as a full-fledged full-stack developer, there are tasks to create various admin panels for internal use, which it makes no sense to transfer to the front-end development team.”
What Other Skills (Java or Otherwise) Should Java Engineers Possess?
Dmitri Ivashenko, lead Unity developer at my.games, tells Dice: “A deep understanding of Java fundamentals is a no-brainer. To be a great Java engineer, one needs to have a firm grasp of the language's basics, including understanding data types, variables, loops, conditionals, classes, objects, inheritance, polymorphism, etc. A strong foundation in these areas is crucial and provides the base for more advanced skills.”
As they advance in their careers, Java engineers should pick up the finer points of the language’s ecosystem principles, including (but not limited to):
- Multi-threading
- Generics
- Collections
- Streams API
- Lambda expressions
- Functional interfaces
- Method references
- Java modules
Yes, this is a lot to learn, but don’t be discouraged—you’re not expected to learn these concepts overnight, and you can often take your time mastering them.
No matter what languages you learn, always keep in mind that all good developers and engineers understand the more abstract principles of building good software and systems. “Knowledge of only one programming language does not make a programmer an engineer,” Glumov reminds us. “An engineer should first be able to design systems using suitable technologies for this, taking care of performance and potential bottlenecks in advance. Knowledge of microservice architecture is necessary today for the development of web applications. Gone are the days when systems were written as monoliths.”
Knowledge of cloud systems and databases is likewise key, especially if you’re working for an organization that wishes to quickly scale apps and services. “Today, tools such as Kubernetes can change the number of microservices instances on the fly, depending on the load on them,” Glumov continues. “They are working with the infrastructure, and supporting the Infrastructure as Code (IaS) approach is an integral part of the work of a backend developer, even if the company has dedicated DevOps engineers for this. It is necessary to know SQL and be able to work with databases. Understand when to use relational databases and when to use NoSQL. Queues have also become integral parts of web applications, and Kafka has become a standard in the industry, and its knowledge is often checked at job interviews. Knowledge of git, CI/CD, and application build tools are also mandatory, as they are used in the daily tasks of Java engineers.”
Landman says: “Java engineers should have in-depth knowledge of Java EE, now known as Jakarta EE, which is a set of specifications for developing enterprise-level applications. Familiarity with servlets, JavaServer Pages (JSP), Java Persistence API (JPA), and Enterprise JavaBeans (EJB) is essential for building robust, scalable, and secure enterprise applications.”
Other frameworks such as Spring will help streamline development. “For Java engineers interested in mobile app development, having in-depth knowledge of Android development is essential,” Landman continues. “Java is the primary language used for Android app development, and understanding the Android SDK and Android Studio is crucial for building Android applications.”
Is a Degree Required to Get a Job as a Java Engineer?
“While a formal degree in computer science or a related field can be advantageous and preferred by some employers, it is not an absolute requirement,” Landman says. “Many companies value practical experience, technical skills, and a strong portfolio of projects. Candidates with relevant certifications and demonstrated expertise in Java programming can also secure positions as Java engineers.”
Glumov adds: “You are lucky if you have received a fundamental education in computer science; it will help you in your career and expand your horizons. However, most developers are self-taught. Sometimes motivation and the desire to change professions can give more knowledge than the years spent at the university. The world of modern development is changing rapidly. To be in demand as a specialist, constantly studying and learning new trends and technologies is necessary. Without this skill, an academic degree will soon lose value.”
