Java

Proficiency in Java, with a good understanding of its ecosystems

Sound knowledge of Object-Oriented Programming (OOP) Patterns and Concepts

Familiarity with different design and architectural patterns

Skill for writing reusable Java libraries

Knowhow of Java concurrency patterns

Basic Understanding of the concepts of MVC (Model-View-Controller) Pattern, JDBC (Java Database Connectivity), and RESTful web services

Experience in working with popular web application frameworks like Play and Spark

Relevant Knowledge of Java GUI frameworks like Swing, SWT, AWT according to project requirements

Ability to write clean, readable Java code

Basic knowhow of class loading mechanism in Java

Experience in handling external and embedded databases

Understanding basic design principles behind a scalable application

Skilled at creating database schemas that characterize and support business processes

Basic knowledge of JVM (Java Virtual Machine), its drawbacks, weaknesses, and workarounds

Implementing automated testing platforms and unit tests

In-depth knowledge of code versioning tools, for instance, Git

Understanding of building tools like Ant, Maven, Gradle, etc

Expertise in continuous integration

Other required skills of java developer include the basic knowledge of:

JavaServer pages (JSP) and servlets

Web frameworks like Struts and Spring

Service-oriented architecture

Web Technologies like HTML, JavaScript, CSS, JQuery

Markup Languages such as XML, JSON

Abstract classes and interfaces

Constructors, lists, maps, sets

File IO and serialization

Exceptions:

Generics

Java Keywords like static, volatile, synchronized, transient, etc

Multithreading and Synchronization