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Hire Top 1% Remote Java Developers in 24 hrs with ultraGenius

Ultragenius is a marketplace for top software developers, engineers, programmers, coders, architects, and consultants. Top start-ups and companies choose developers from Ultragenius platform for their critical software projects. Hire from Ultragenius network & scale your engineering team in a matter of few days. 

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Senior Java Developer

Rishabh is a software engineer having 7+ years of experience in developing server-side web applications. He has majorly worked in Big data and Android development.

Expert in






10 Years


Full Time


Remote Java Developer

Mahesh is a remote Java developer having 7+ years of experience working on backend development projects and developing microservices in Java.

Expert in






10 Years


Full Time


Fully Remote Java Developer

John is a software engineer having 10+ years of experience developing server-side applications and has majorly worked in system design and developing service-oriented architecture .

Expert in






10 Years


Full Time

Hire top Java developers with Ultragenius

Java is one of the widely used object-oriented programming language designed to have as minimum implementation dependencies as possible in an application. Java is an evergreen language used on both client-side and server-side.

What Ultragenius offers?

Fast Hiring

ultraGenius ensures that top quality developers with the most talent are hired in less than 72 hours.

Intelligent Matching

The matches are specifically curated as per your needs. We dim fit 3 skills - Tech, Culture, and Context Fit.

Rigorous Vetting

ultraGenius conducts tests and ensures that only the most suitable developer with the best skills is hired.

Hire dedicated Java developers through Ultragenius in 4 easy steps

Tell us the skills you need

We’ll schedule a call and understand your requirements.

We find the best talent for you

Get the list of pre-vetted candidates in days.

Schedule the interviews

We will arrange a call after understanding your requirements.

Begin your trial

Start working with Ultragenius with a 1-week trial period.

Our Happy Clients

UltraGenius is the best remote talent network to meet with brilliant developers who are most talented and skilled in the technical field. UltraGenius provides the most fit developers who not only match our job requirements but also our company's culture and working environment.
Once you are part of UltraGenius, you don't have to look for another platform which can find the top skilled developers with same effort as UltraGenius. UltraGenius's vetting tests and assessments are unmatchable and provides the perfect match for the job role.
Our company is thankful to UltraGenius wholeheartedly. UltraGenius's pace of finding the top 1% developers is unmatchable. Not only UltraGenius developers are the ones who match our job requirements but also the best fit to our company's working culture .
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Want to hire Java developers on your own? Here are the skills you must look for while hiring a remote Java developer

Hiring Java developers might be a complex task for you if you are a non-technical manager. Java is an evergreen programming language used for developing both client-side and server-side applications and its flexibility to get used in Android development and Big Data Analytics makes it one of the highest demanding skills of the 21st century. But, here comes the challenge, how to hire the most suitable dedicated Java developers who exactly match your job applications. No worries, Ultragenius comes to assist you while recruiting the top skilled Java developers on your own. Ultragenius understands your job requirements and gets you only the proficient Java developers who have in-depth knowledge in developing software applications.

The following skills you must look while recruiting a Java developer – 

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Strong understanding of Object-Oriented Programming Skills (OOPS)-

Object-Oriented Programming is one of the most essential skills of a Java developer. To develop real-world applications, binding data members and functions are mostly required and to achieve loose coupling among the classes.

  • Encapsulation – Encapsulation is binding the related data members or variables and functions inside a single unit called class. This mechanism prevents the code from accessing outside a particular class. Encapsulation is achieved by declaring the variables of a class as private and using the getter() and setter() methods to access them indirectly ensuring security.
  • Inheritance – Inheritance is one of the widely used concepts in real-world programming that allows one class to extend the functionality of other classes and use its member functions instead of writing again multiple lines of code.
  • Abstraction – Abstraction is required when we have to define a parent class that contains only the structure of a given project and the implementation has to be done by its child class. Abstraction is the mechanism of hiding the data implementation and showing only the necessary details.
  • Polymorphism – Polymorphism allows an object to behave differently on its invocation. There are two types  – Compile-time Polymorphism and Run-time Polymorphism. 

In Compile-time Polymorphism, the methods with the same name behave differently according to the number of arguments and return type. 

For example, 

int mul (int a, int b) {

 return a*b;


double mul (double a, double b){ 

return a*b;


In Run-time Polymorphism, the overridden method is invoked by the parent class reference and it determines which method to call based on the object created. 

class Bike{ 

void run(){



} class Bajaj extends Bike{ 

void run(){

System.out.println(“running safely with the avg. speed of 20km/hr”);



public static void main( String[] args ){

Bike bike = new Bajaj();;

Output is  –  running safely with the avg. speed of 20km/hr.

Besides these four concepts, the Java developer must also know about Composition, Association, and Aggregation. 

Familiarity with the core HTML, CSS, and Javascript

To develop a full-stack applications in Java,  the knowldege of HTML, CSS, and Javascript is required in designing an excellent User Interface (UI). The developer must know more than one Javascript library framework like jQuery, Bootstrap and must be specialized in working with Asynchronous Javascript and XML (AJAX). Check if the developers have worked with Javascript build tools such as Grunt.js, Gulp.js, and Bower.js.

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Experienced implementing Design Patterns in Java

  • Experience implementing Design Patterns in Java

It is a must-required skill for any Java developer to know about the design patterns and utilize them in developing system architecture. Every design pattern is a blueprint. Here are the important design patterns every developer should know –
Creational Design Pattern, Structural Design Pattern, Behavioral Design Pattern, JEE Design Pattern.

Creational Design Patterns are mainly concerned with the process of creating objects.

Structural Design Patterns are responsible for composing classes and objects which form larger structures.

Behaviour Design Patterns are responsible for establishing interaction between objects.

JEE Design Patterns are responsible for providing solutions to Java Enterprise Edition-based software applications.

  • Creational Design Patterns are Singleton Design Pattern, Builder Pattern,  Factory Method, Abstract Factory, and Prototype Pattern.
  • Structural Design Patterns are Adapter, Bridge, Composite, Facade, Flyweight, Proxy.
  • Behavioral Patterns are Command, Mediator, Iterator, Chain of Responsibility,  Observer, Memento, Template Method, Observer, State, Strategy, and Visitor. 

The Java developer must also be familiar with – Layered Pattern, Client-server Pattern, Master-slave Pattern, Pipe-filter Pattern, Peer-to-Peer Pattern, Broker Pattern, Event-bus Pattern, Model-View-Controller Pattern, Blackboard Pattern, and Interpreter Pattern.

Strong understanding of SOLID Principles -

Understanding SOLID principles is the core skill required for any Java developer. Java is designed to reduce dependencies among classes so that software engineers can work in modules easily and change one part of software without affecting the other. SOLID stands for – Single Responsibility Principle, Open/Closed Principle, Liskov Substitution Principle, Interface Segregation Principle, and Dependency Inversion Principle. 

Single Responsibility  – Each class is responsible only for one thing and serves only one part of the software’s functionality. It ensures loose coupling by limiting the scope of classes.

Open/Closed Principle – Classes, functions, and modules are open for extension, but close for modification. This means new functionality can be added in a class but it must not modify the existing code.

Liskov Substitution Principle – Every derived class should be substitutable for its base class. The subclass can replace the base class and must keep the program behavior unchanged.

Interface Segregation Principle –  A class should not be forced to implement an interface that it does not use.

Dependency Inversion Principle – The classes should depend upon abstract classes or interfaces instead of directly implementing concrete classes or functions.


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Proficient using Microservices -

Microservices is a well-known software design architecture designed to overcome the disadvantage of traditional monolithic architecture. Loose coupling in software development is achieved with the microservices which break a large software application into smaller, independent, and loosely coupled modules on which various developers in a team can work separately. 

Advantages of Microservices – 

  • Failure of a single module will not affect the other modules.
  • Since the modules are separate, you can increase the scalability of the module which is needed more at the appropriate time as compared to increasing the scalability of the whole application.
  • The deployment becomes much faster as the codebases are small.
  • Microservice provides the flexibility to work on a new technology stack on an individual part of code and because of loose coupling rolling back changes becomes easy.

Immense knowledge working with DevOps -

Java developers require DevOps skills for Continuous Integration and Continuous Deployment (CI/CD). Java Developers must know –

  • Programming best practices
  • Building scripts and guidelines
  • Creating an infrastructure environment.

The main DevOps tools which a Java developer must know are –

  • Continuous Development – Git, SVN, Jira, Mercurial, CVS.
  • Continuous Integration – Bamboo, Jenkins, Hudson
  • Continuous Delivery – Tomcat, Nexus, Archiva.
  • Continuous Deployment – Docker, Chef, Puppet.
  • Continuous Monitoring – ELK Stack, Nagios, Splunk.
  • Continuous Testing – Katalon Studio, Selenium, Appium, Eggplant, Watir, Tosca.

Experienced in working with Version Control System (VCS)

Hire Java Developers need to be familiar with different version control systems, such as Git for their work. It is the system that helps a team collaborate and organize code, maintain frequent changes in code. Git also assists in reviewing old codes (and comparing them) against newly updated codes; pulling the code from repository or managing commit history.

Along with this, developers need to know how to use add, push, pull, commands; branching and merging which allows them to work independently on their contribution while still co-ordinating amongst each other’s efforts.

Knowldege of Spring Boot

A Java developer must know about Spring Boot, an open-source microservice framework. Spring Boot helps developers to create web applications without the need for any external server, reduces development time, and increases the efficiency of an application. It embeds a web server like Tomcat or Jetty in its application. Spring MVC defines each dependency separately and groups them into a single unit. Also, it simplifies the integration with other Java frameworks like – Hibernate ORM / JPA, Struts/JSF, etc.   Spring Boot provides CLI tools for creating and executing web applications. Spring Boot provides support for the following – 
  • Project Support
  • Starter Project Wizard
  • Command Line Interface (CLI)
  • Hibernate ORM / Java Persistent APIs (JPA)
  • Spring Initializr
  • Annotations
  • Java Database Connectivity (JDBC)
  • Starters
  • Actuator
  • Transaction Management.

Knowledge of MVC Architecture

MVC stands for Model-View-Controller architecture. MVC design pattern separates the application logic from the view logic (user interface) while developing software. It consists of three layers mainly – 
  • Model – Model represents the business layer of an application.
  • View – View is the User Interface of an application.
  • Controller – Controller manages the application flow.

In the context of Java programming, 
  • The Model consists of Java classes, 
  • The View is responsible for displaying data,
  • The Controller provides the retrieved data to the View and the View is rendered and sent back to the browser to display the data to the client. 
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Experience with web markup and UI, UX Concepts

The developer must have a firm understanding of element positioning, displaying the elements, and making components interactive, semantic markup, and other related UX Concepts so they can design the product with the best quality. The developer must be experienced in developing visual effects in presentational markup. For, example – How the heading appears, making text larger and putting weight to it, and giving which color to it, and which markup can include captions, bind columns, and row headings to table cells. 

Strong grasping on JVM internals

While hiring a Java developer, make sure the developers know the following JVM internals – 
  • JVM Options
  • JIT
  • Garbage Collection
  • Race Conditions
  • Concurrency Handling
  • CPU and RAM Connection
  • Collector
  • Performance Bottlenecks
  • Execution Model

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Connect with the top 1% Java developers of the world at the lowest prices

Java is a robust programming language because of its flexibility to work on both client-side and server-side. Large number of remote java developers are competing to get hired. Ultragenius filters out the most skilled dedicated Java developers to connect you only with the top 1% among 20K+ remote Java developers.

Top Interview Questions to ask while hiring a Angular.js developer

Constructor Overloading in Java is the concept of having different definitions of a constructor based on different parameters, so that each constructor can perform a different task from another. Consider an example,

public class Bank{ 
public Bank(){

System.out.println(“This is a default constructor”);

public Bank (String name){

System.out.println(“Bank name is  :” + name);

public static void main(String[] args){ 

Bank bank = new Bank (); 
Bank bank2 = new Bank(“Bank of India”);



Output - 

This is a default constructor

Bank name is Bank of India

this() is used to call the current class constructor in Java. 

public class Bank{ 

public Bank(){


System.out.println(“This is a default constructor”);


public Bank (String name){

System.out.println(“Bank name is  :” + name);

public static void main(String[] args){ 

Bank bank = new Bank (); 

Bank bank2 = new Bank(“Bank of India”);



Output - 
Bank name is Bank of India
This is a default constructor

  • When a variable is final, its value cannot be changed, but when a variable is static only one copy of that variable is shared among all the objects of the class.
  • A final method cannot be overridden by its child class whereas a static method can be invoked without creating the object of the class containing that method, it may/may not get overridden by its child class. For example, main method in Java  is static because it has to be loaded before the  instantiation of a class takes place.
  • To restrict the inheritance of a class, final keyword is used with the class so its child class cannot extend it whereas a class can be declared static only when it is a nested class in Java, the advantage is that objects of a static class can be created without any need of creating the instance of its outer class.

For example, 

class Demo{ 

class A{} 

static class B{} 

public static void main(String[] args){ 

A a = new A(); /* it will show compile time error, you need an instance of Demo to instantiate A;*

B b = new B(); /*it will compile successfully, no instance of Demo needs to be created to instantiate B.*/



Constructor call is always the first statement. Either you can use this() inside the constructor or super(), this() is used to invoke the current class constructor of a class, while super() is used to invoke the parent class / superclass constructor of that class.


The main method in Java is - public static void main(String[] args) Every word in main method conveys a meaning to the JVM - 
    • public - The keyword public indicates that main method is accessible globally as it is the entry point of the program execution so JVM can invoke it from outside the class.
    • static - The main method has to be invoked even before instantiating that class, so it is declared as static.
      • void - In C++, the return type of main method is declared as int, which indicates the exit code status of a program which is the process of Operating System, return 0 means program executed successfully and non-zero exit code means there is an error in the program. These programs are the sub-process of the main process which after receiving their exit code cleans up the sub-process from the process table and frees the memory allocated to that process, that is why it is compulsory to pass exit code for the C++ programs. But in Java, the program runs as the main thread and there is no direct allocation of resources to a Java program. That is why main method in Java does not return anything.
      • main - main is the starting point the JVM looks for when executing a Java program.
    • String[] args - It is an array of java.lang.String class. String[] args can also be written as String...args or String args[], which accepts command line arguments.
JVM stands for Java Virtual Machine. It is a run-time environment that takes Java bytecode as input and converts it into assembly or machine code line-by-line. The memory areas allocated by JVM are - 
  • Class (Method) Area

  • Heap

  • Stack

  • Program Counter Register

  • Native Method Stack
  • Class (Method) Area - This memory stores data at the class level like method data, runtime constant pool, and program code of methods.
  • Heap - Heap is used for dynamic memory allocation.
  • Stack - In JVM, the Stack is used to store frames. Every time a method is invoked, a new frame is created and destroyed when the invocation completion.
  • Program Counter Register - A JVM thread that performs a specific task of a method has a program counter associated with it. 
Native Method Stacks - Native method stacks are also called as C Stacks. This memory can be fixed or dynamic and is allocated for each program thread when the thread is created.

this keyword in Java is used in - 

  • Referring to class variable when both, class variable and local variable have same name.
  • Invoking the current class constructor.
  • Passing it as an argument in method call.
  • Passing it as an argument in the constructor call.
  • Returning the current class object from the method.

Aggregation represents one-to-many relationship and is unidirectional in nature. Aggregation defines has-a relationship. Both the objects in aggregation can exist independently which means ending one object doesn’t affect another entity.  For example, Bank has-a Customer, if Bank gets destroyed Customer will still remain. Aggregation is a weak association. Code resusability is best achieved by Aggregration. 

Composition defines a part-of relationship, i.e., child cannot exist independent of the parent. For example, engine is a part-of the car. If the car gets destroyed, then engine also gets destroyed. Composition is a strong association. Multiple Inheritance which cannot be achieved by Inheritance, can be achieved by Composition. 

  • Java Server Pages (JSP) use Java inside HTML provides ease to the developer to write, debug, and edit the code whereas Servlets use HTML in Java which makes the code complicated. 
  • Servlets use println statements for printing an HTML doucment whereas JSP does not.
  • View logic and Business logic is separated in JSP which is not possible in Servlet.

If you are trying to hire a Java Developer. Here is the Java Developer Job Description that you can use in your hiring.

Frequently Asked Questions

Ultragenius is one of the leading platforms for hiring remote talent and connecting developer and part-time developers with Silicon Valley businesses. We focus on finding the best talents who will perform extremely well and will be easily integrated into your teams. We filter out only the top 1% most skilled developers among the 20K+ developers who have applied on our platform. Candidates have to prove their self-reported experience by giving Ultragenius’ s skill tests.

Ultragenius first tests the developer’s skill set by conducting a two and half hour hiring test. Our hiring test judges a candidate on all aspects like aptitude, case study analysis, verbal and reasoning, coding questions based on data structures and algorithms, software engineering, system design, and more. Then, there is another round for the candidates who are selected from this round called “Higher-level Assessment Skill Test”, which is a video round that deeply analyzes developers’ major skills and asks questions about the projects they have worked upon.

Fill up the form which is on every hiring freelancers’ page and we will inform you once we select the top 1% Java developers matching your job requirements.  After analyzing the candidates based on their resumes and two assessment tests, we provide you the feedback quickly. And if the developers selected by our team are fit for your job role, then we also provide the onboarding.

Ultragenius offers you only the most skilled developers who are top 1% among the 20K+ developers who have applied on our platform. After a rigorous selection and testing process, we sort out only the top candidates for you. You can check out Ultragenius’ s selection process for hiring Java developers on


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