Vert.x - the Java framework for Busy Servers
Table of Contents

Vert.x - the Java framework for Busy Servers

Imagine a bustling coffee shop with a long queue of customers eagerly waiting for their caffeine fix. The baristas are busy brewing and serving cups of steaming hot coffee, while the cashier is swiftly handling payments. It's a chaotic scene with everyone rushing to get their orders, and any delay could lead to frustrated customers.

During this chaos, there's one barista who seems to be effortlessly managing the rush. He's quickly taking orders, brewing coffee, and handling payments with ease, all while keeping a friendly smile on his face. Curious, you approach him and ask how he's managing to handle the crowd so smoothly.

This anecdote illustrates the power of Vert.x framework in handling high-concurrency and demanding situations. Just as the barista relies on Vert.x to keep the coffee shop running smoothly, developers can rely on Vert.x to build fast, responsive, and scalable applications that can handle large workloads, making it a meaningful change in the world of software development. In the next part of article, we try to introduce key aspects of Vert.x framework and differences between widely used and popular Spring/Spring Boot.

In the next parts of the article, we will cover following topics:

  • What is Vert.x?
  • Who uses Vert.x around the World
  • When to use Vert.x
  • Get the coffe! – simple Vert.x application
  • Vert.x vs Spring
  • Pros & Cons
  • Summary

What is Vert.x?

Vert.x is a modern framework that helps build fast and scalable applications, just like a skilled barista brewing coffee. It handles tasks efficiently, like multitasking, without getting stuck or delayed, ensuring smooth performance even under heavy workloads. It avoids using threads that can block or slow down, just like a barista serving customers without getting overwhelmed. Vert.x allows for efficient resource use, faster development cycles, and the ability to build reliable applications that can handle many requests at once, just like a barista serving coffee to a busy crowd.

  1. Vert.x helps build modern, high-performance applications: Vert.x is a tool that helps developers create applications that are efficient, fast, and responsive. It's designed to handle a lot of work at the same time, making it great for applications that need to handle many things happening at once.
  1. Vert.x works with different programming languages: Vert.x can be used with different programming languages like Java, Kotlin, Scala, JavaScript, Groovy, and Ruby. This means that developers can use the language they're most comfortable with or the one that's best for their specific project.
  1. Vert.x is good for big applications: Vert.x is built to handle large applications that need to be spread out across many computers or servers. This makes it useful for applications that need to handle a lot of users, data, or information at the same time.

Who uses Vert.x around the World?

There are several well-known companies and organizations that use Vert.x in their technology stack. Vert.x is used by “well-known” companies like Uber, Netflix, Capital One, Red Hat, Nokia, ING Bank, Domino's, Zalando, Intel, Huawei.

These companies use the strengths of Vert.x, to build scalable, resilient, and responsive applications that handle substantial amounts of concurrent connections and high throughput. Vert.x has gained popularity among these and many other organizations for its ability to build modern, distributed, and fast systems that can handle the demands of today's fast-paced and highly concurrent digital world.

When to use Vert.x?

As a business analyst or manager, understanding the strengths of Vert.x compared to Spring is crucial for making informed technology decisions.  

Factors such as performance, language flexibility, resource efficiency, real-time capabilities, and ease of adoption should be carefully considered for the best application development.

Following points show aspects, in which the Java framework is :

  • Performance and Scalability: If your application needs to handle many concurrent connections or real-time events, Vert.x's high-performance and scalable nature may be a better fit compared to Spring.
  • Flexibility in Language Choices: Vert.x allows developers to use different programming languages like Java, Kotlin, or JavaScript, which provides flexibility and options for choosing the best language for various parts of the application.
  • Resource Efficiency: Vert.x's lightweight footprint makes it suitable for building microservices or serverless applications, allowing efficient use of system resources.
  • Real-time and Responsive Applications: Vert.x's event-driven architecture is well-suited for building reactive and real-time applications that require quick response times and handle high concurrency.
  • Ease of Adoption: Vert.x has a relatively low learning curve, making it accessible for developers who are new to the framework, enabling faster development and deployment cycles.

Get the coffee!

Simple Vert.x application, which utilizes REST and allows to get a “coffee cup” without “waiting in a queue”:

import io.vertx.core.Vertx;
import io.vertx.core.http.HttpMethod;
import io.vertx.ext.web.Router;
import io.vertx.ext.web.RoutingContext;

public class CoffeeApp {
  public static void main(String[] args) {
    Vertx vertx = Vertx.vertx();
    Router router = Router.router(vertx); // Define a REST endpoint for "/coffee/cup" 
    router.route(HttpMethod.GET, "/coffee/cup").handler(CoffeeApp::handleCoffeeCupRequest);
    vertx.createHttpServer().requestHandler(router).listen(8080); // Start the HTTP server on port 8080} 
    // Handler for "/coffee/cup" endpoint 
    private static void handleCoffeeCupRequest(RoutingContext routingContext) {
      // Handle the request asynchronously 
      routingContext.vertx().executeBlocking(future -> {
        // Simulate fetching data or processing a long-running task 
        try {
          // Simulate delay of 1 second 
        } catch (InterruptedException e) {
        // Send the response 
        future.complete("Here's your fresh cup of coffee!");
      }, result -> {
        if (result.succeeded()) {
          // Send the response to the client 
        } else {
          // Send an error response to the client 
          routingContext.response().setStatusCode(500).end("Error occurred while processing request.");

As we can see, building Java Vert.x application from scratch is quite easy and effortless.

Vert.x vs Spring

While Spring is a popular and a widely used framework for building Java-based applications, Vert.x offers unique features and advantages that may make it a better fit for certain use cases. Here are some reasons why one might consider using Vert.x instead of Spring:

  1. Reactive Programming: Vert.x is designed from the ground up to support reactive programming, which allows for efficient handling of asynchronous I/O operations. This makes it well-suited for building highly scalable and responsive applications that need to handle a large number of concurrent requests.
  1. Polyglot Language Support: Vert.x supports multiple programming languages, including Java, JavaScript, Kotlin, and more. This makes it a great choice for organizations that want to leverage the strengths of different languages in their application development.
  1. Lightweight and High Performance: Vert.x is known for its lightweight footprint and high performance, making it suitable for building microservices and distributed systems that require efficient resource utilization and fast response times.
  1. Event-Driven Architecture: Vert.x follows an event-driven architecture, where tasks are handled asynchronously in response to events, such as user requests or messages. This makes it well-suited for building reactive, real-time, and event-driven applications.
  1. Flexibility and a Gentle Learning Curve: the lightweight framework offers flexibility in terms of architecture, deployment options, and integrations with other technologies. It also has a relatively low learning curve, making it accessible for developers who are new to the framework.

Of course, the choice between Vert.x and Spring depends on the specific requirements of the project and the ability of the development team. Both frameworks have their strengths and are widely used in industry. It's important to carefully consider the needs of your application and the skills of your development team when deciding which framework to use.

Vert.x Spring
Reactive Reactive
Higher Scalability & Concurrency
Lower Scalability & Concurrency
Resource Efficient
Resorce Hungry
Lower Learning Curve
Higher Learning Curve

Some terms may sound difficult, so let’s clarify them a little:

Reactive refers to the ability of a system or framework to quickly respond to changes or events in a timely and efficient manner. In the context of Vert.x, being "reactive" means that the framework is designed to handle multiple requests and events concurrently, without blocking or slowing down the overall system. It allows applications built with Vert.x to efficiently handle many concurrent connections and events in a responsive and scalable manner, providing high performance and low latency.  

Consider it a fast-paced game of ping pong in which the system responds to incoming requests and events without missing a beat, ensuring smooth and efficient operations.

Polyglot refers to the ability of a system or framework to support multiple programming languages. In the context of Vert.x, being "polyglot" means that the framework allows developers to write application code in multiple languages, such as Java, JavaScript, Groovy, Ruby, and more. This flexibility allows developers to choose the language they are most comfortable with or the one that best suits their specific application requirements. It also enables reusing existing code or libraries written in different languages within the same Vert.x application.  

Vert.x is flexible and extensible enough to meet the needs of a wide range of development projects, much like a toolbox filled with a variety of implements for various jobs.

Event-driven refers to a programming approach where the flow of an application is determined by events or triggers that occur at different times, rather than following a fixed sequence of steps. In an event-driven system, events or changes in the system, such as user inputs, data updates, or external signals, drive the execution of the code.  

When an event occurs, the associated code or function is triggered to handle that event, allowing the application to react and respond dynamically to changing conditions. In the context of Vert.x, being "event-driven" means that the framework is designed to handle events efficiently, allowing developers to write code that responds to events in a reactive and asynchronous manner. This approach enables Vert.x applications to be highly scalable, responsive, and adaptable to changing conditions, making it ideal for building real-time and interactive applications.  

Think of it like a game Simon says, where the actions are determined by the events or instructions given, allowing the application to respond and adapt accordingly.

Pros & Cons

Pros of using Vert.x:

  1. Responsive and efficient: Vert.x's reactive and event-driven approach allows for scalable and efficient applications that can handle concurrent connections and real-time events.
  1. Language flexibility: Vert.x supports multiple languages, providing flexibility for developers.
  1. Lightweight: Vert.x has a small footprint, making it suitable for microservices or serverless applications with efficient resource utilization.
  1. High performance: Vert.x is known for its excellent throughput and low latency due to optimized I/O operations and non-blocking concurrency.
  1. Easy to learn: Vert.x has a relatively low learning curve, making it accessible for developers to quickly get started.

Cons of using Vert.x:

  1. Smaller community and ecosystem: Vert.x may have a less mature community and ecosystem compared to some established frameworks like Spring.
  1. Limited enterprise features: Vert.x may not have comprehensive enterprise-focused features such as robust security and monitoring.
  1. Limited expertise: Finding experienced developers with Vert.x expertise may be challenging compared to more established frameworks.
  1. Learning curve for non-Java developers: Non-Java developers may need to familiarize themselves with Java concepts when using Vert.x in a non-Java language.

Consider these pros and cons in the context of your project requirements, team expertise, and technical strategy.


Vert.x is a cutting-edge, reactive, and event-driven framework that enables building high-performance, scalable, and responsive applications. Its lightweight nature, language flexibility, and efficient concurrency make it suitable for a wide range of modern application development needs. Vert.x's key strengths lie in its ability to handle concurrent connections, real-time events, and deliver excellent performance with low latency. It is easy to learn for developers, making it accessible for quick adoption.

However, Vert.x also has some considerations to keep in mind, including its smaller community and ecosystem compared to established frameworks like Spring, limited enterprise features, and potential challenges in finding experienced developers with Vert.x expertise. Despite these challenges, Vert.x is a powerful tool for building modern applications that require high responsiveness, scalability, and performance.

In conclusion, Vert.x is a compelling choice for organizations that prioritize reactive, event-driven, and high-performance application development. It is worth considering in the context of your specific project requirements, team expertise, and technical strategy to determine if it aligns with your business goals and development needs.

Liked the article? subscribe to updates!
360° IT Check is a weekly publication where we bring you the latest and greatest in the world of tech. We cover topics like emerging technologies & frameworks, news about innovative startups, and other topics which affect the world of tech directly or indirectly.

Like what you’re reading? Make sure to subscribe to our weekly newsletter!

Join 17,850 tech enthusiasts for your weekly dose of tech news

By filling in the above fields and clicking “Subscribe”, you agree to the processing by ITMAGINATION of your personal data contained in the above form for the purposes of sending you messages in the form of newsletter subscription, in accordance with our Privacy Policy.
Thank you! Your submission has been received!
We will send you at most one email per week with our latest tech news and insights.

In the meantime, feel free to explore this page or our Resources page for eBooks, technical guides, GitHub Demos, and more!
Oops! Something went wrong while submitting the form.

Related articles

Our Partners & Certifications
Microsoft Gold Partner Certification 2021 for ITMAGINATION
ITMAGINATION Google Cloud Partner
© 2024 ITMAGINATION. All Rights Reserved. Privacy Policy