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Enterprise Service Bus vs Microservices. Who Wins the Game?

When a company is ready to go digital, a big question is what kind of tech setup to use. Should they go with something like an ESB architecture, use microservices, mix them, or try something new? With so many choices, the company needs to think about why one option might be the best out of all of them. Further, we will showcase the peculiarities and comparison of both.

What is enterprise service bus architecture?

The ESB definition is simple: it uses a single software piece to link various applications offering an array of services within a service-oriented architecture. This pattern creates pathways for data to flow between, acting like a bus system that assigns tasks, such as message direction and separation, to different parts of an application. Such a setup means applications exchange information via the ESB technology instead of connecting directly, eliminating the need for developers to craft specific integrations for every application.

Key enterprise service bus features

Independent interaction. Enables systems to interact without direct dependencies.

Message refinement. ESB technology facilitates the modification and enhancement of notifications, including format alterations and additional information appendages.

Flexible protocol handling. It supports varied communication protocols, ensuring seamless interaction between differing systems.

Dynamic direction and protection. ESB directs queries to appropriate services based on set criteria while ensuring defence against unauthorised system access.

Standardisation of a data format. Transforms message data into a specific format and structure for uniformity.

Coordinated transaction oversight. Provides a mechanism for managing and unifying transactions across multiple and varied systems.

Enterprise Service Bus (ESB)

Enterprise service bus examples and use cases

Sprint, a major player in telecommunications, shifted from costly and complex middleware solutions like Oracle WebLogic to a more efficient ESB technology, adopting JBoss. This move led to significant financial savings, specifically an annual reduction of $4 million in expenses.

With the JBoss ESB, Sprint’s internal development team gained substantial autonomy over system integrations, benefiting from the adaptable and collaborative nature of the open-source platform. JBoss ESB, particularly JBoss Fuse, stands out as a contemporary choice derived from the Apache open-source ecosystem, showcasing how such solutions can rival established, proprietary middleware systems.

Sprint’s experience highlights the value of ESB solutions in modernising enterprise system integrations, providing cost savings, and improving developer engagement.

The details about microservices

Microservices architecture is a method of constructing applications by deconstructing larger software systems into smaller, self-contained services. These individual services are designed to operate in tandem yet maintain a loose pairing, similar to interchangeable components within a larger, modular IT framework.

In this architectural paradigm, the application consists of numerous distinct services that are built, launched, and expanded autonomously. Interaction between them is facilitated through explicitly established APIs, commonly using REST (Representational State Transfer) protocols or message queuing systems. This structure allows for a flexible and scalable approach to application development and infrastructure management.

Key principles of microservices

Self-reliant elements. At the heart of microservice architecture are independent components—software packages, applications, or modules—each capable of modification and deployment without affecting the app’s stability.

Seamless integration. These components form a cohesive unit to deliver seamless user interactions and business functionality, encompassing services from back-end processing to front-end interaction and beyond.

Accurate communication. Components communicate through clear protocols such as REST, RPC, or event-driven interfaces, with each microservice presenting a well-defined API for ease of use.

Ownership and agility. Adopting best DevOps practices while working with microservice architectures empowers teams to develop and manage their services.

Key principles of microservices

Microservices’ best work examples

Netflix stands as a prime example of the transformative impact of microservices. Initially, this streaming giant kicked off with a single, unified software application. Its rapid expansion brought about significant hurdles, particularly in handling tons of user requests. This situation frequently resulted in database overloads.

In response, Netflix transitioned its localised database system to a cloud infrastructure provided by Amazon Web Services.

The shift made developers break down the existing monolithic framework to facilitate the migration to the cloud. Observing the benefits of this segmented architecture, Netflix dedicated two years to convert entirely to a microservices’ structure. This change not only addressed their immediate issues but also set the stage for more robust and scalable service delivery.

Real-life cases of enterprise service bus vs microservices implementations

ESB implementations

A big home building company must connect its construction planning software with the customer service system and other apps like payroll and travel expenses. IBM used its ESB tool, which had special plugs or “connectors” already made for these types of work. This made it much easier to connect all the company’s systems, making one big, well-organised network instead of having lots of little, separate connections.


Uber’s application was built on a monolithic architecture, a singular codebase encompassing all its functionalities - from matching drivers with passengers to processing transactions and managing trips.

However, the swift company’s growth showcased the limitations of the monolithic structure, particularly in terms of scalability. The need to deploy the entire codebase for every update, irrespective of its significance, was both resource and time-consuming. Even a tiny modification necessitated comprehensive testing caused by the interconnected nature of the codebase.

A solution was found, and Uber transitioned to a microservice architecture. By segmenting its application into multiple microservices, the company could isolate functions such as billing, trip management, driver management, and notifications. This strategic approach positively influenced company services.

How to choose between ESB architecture and microservices?

Growth trajectory. If the current monolithic system is blocking a business’s growth due to its lack of flexibility and scalability, microservices might be the better option.

Scaling needs. For firms that need the ability to scale quickly—especially in a cloud environment where real-time data and high volumes are involved—microservices can offer more agility.

IoT integration. For developing an extensive network of IoT devices, microservices are often more suitable because of their ability to handle large-scale, horizontal expansion and the high volume of data that IoT networks generate.

Improved analytics. To leverage advanced ML and AI for business intelligence, a cloud-based microservices architecture can provide the necessary resources.

Specialised development. If the company concentrates on developing a unique service while integrating a pre-built one to complete the application, microservices allow it without creating everything from scratch.

Cost and time efficiency. Microservices can save time and resources on revamping and maintaining IT infrastructure, as they allow for targeted updates and more straightforward control.


Choosing between ESB architecture or microservices — demands a strategic consideration of the company’s present needs and future goals. Success stories from industry leaders offer valuable insights into the transformative benefits of these technologies. Due to the complexities of the current business landscape, a well-informed decision on infrastructure can be a catalyst. Whatever the choice, the journey toward technological modernization is a pivotal step for unlocking new possibilities and driving business growth.


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