At Inspired, two programming frameworks are backbones to nearly everything we’ve built: Spring Boot and Phoenix. They really represent two different philosophies in such a way that most people are surprised when they hear that we use both.
But don’t get me wrong, we love using both: It’s like having two different specialists on a team – each being masterful at his own respective field and yet coming together to solve the problems at hand in their own unique way. This is not a comparative article between the two; it’s about sharing the journey of why we use both and how you can decide which one is right for your next project.
Although I’m pretty sure that a lot know what each of those technologies are, here is a quick recap what each of them is.
Overview of Spring Boot
What is Spring Boot?
Spring Boot is an open-source, Java-based framework for building standalone, production-grade web applications with minimal operational overhead. In other words, Spring Boot is basically developed on top of the Spring framework, and it is far simpler to configure and construct new applications. Spring Boot can build applications that have less code and less development time since it carries a lot of non-functional features out of the box, which is common to large types of projects.
It follows the convention over configuration approach, minimizing the number of configuration files. Spring Boot allows easier launching and running with Tomcat, Jetty, or Undertow as an embedded server. That’s why it’s gaining so much popularity for the microservices architecture.
Spring Boot also uses a very rich ecosystem of libraries and tools, including Spring Data, Spring Security, and Spring Cloud, among others. Each integrates well to provide out-of-the-box solutions for enterprise applications.
Advantages of Using Spring Boot
One of the key benefits of using Spring Boot is its ease of use. The framework autoconfigures itself out of the box, saving the developer from cumbersome configuration settings. Particularly useful in small to medium-sized projects where time-to-market is critical.
All this is reasonably easy to learn-from the extensive Spring Boot documentation down to active community support – meaning it’s available for developers of any experience. Further sweetening it, numerous tutorials, guides, and forums avail themselves so that assistance is never too far away.
Another important advantage of Spring Boot is that it really allows for immense flexibility in integrating with almost all kinds of databases, messaging systems, and cloud services. This again makes it very apt for building scalable, cloud-native applications which can seamlessly adapt to ever-changing business needs.
Overview of Phoenix
What is Phoenix?
Phoenix is a web development framework written in Elixir, which itself is a functional programming language that runs on top of Erlang VM. It enjoys high concurrency and fault-tolerant features with ease, hence allowing Phoenix to manage large-scale applications. Availing yourself of the power of Elixir, Phoenix will allow you to have a robust, scalable, and maintainable platform for web development.
This framework is particularly well-suited for real-time applications, given that it has built-in support for WebSockets and channels. Phoenix has, therefore, become one of the finest frameworks when it comes to applications and collaboration tools that need to update stuff live.
One of the most powerful aspects of Phoenix is its support for LiveView, which enables real-time, dynamic user interfaces directly from the server—without the need for custom JavaScript frameworks or APIs. This makes development extremely fast and simplifies the frontend/backend integration. Like Spring Boot, Phoenix also follows the MVC (Model-View-Controller) pattern and a “convention over configuration” philosophy, which contributes to maintainable, clean, and efficient codebases.
Advantages of Using Phoenix
One of the strong features of Phoenix is handling high concurrency. Thanks to the Erlang VM, Phoenix can efficiently manage thousands -or even millions- of simultaneous connections, making it a natural fit for real-time, high-traffic applications. While JVM-based frameworks like Spring Boot also deliver excellent performance—especially in compute-heavy tasks—the lightweight process model of the Erlang VM offers unique advantages for workloads centered around persistent connections and rapid message passing.
This framework encourages developers, through the paradigm of functional programming, to write code that is clean, concise, maintainable, and with fewer bugs. This is because the approach is easier to reason about for application behavior; hence, applications are more reliable and robust.
Phoenix is also plugged into the Elixir ecosystem, having some well-integrated tools at your disposal for accomplishing database operations with Ecto, or for testing with ExUnit, among others. Combining those with what Phoenix brings to the table gives you a truly comprehensive development experience that really ramps up productivity and code quality.
Comparing Spring Boot and Phoenix
Performance and Scalability
Regarding performance, Phoenix enjoys a better position because of the high concurrency handling. Due to lightweight processes of Erlang VM and message-passing capability, Phoenix handles a couple of thousand connections out of the box for real-time applications.
Spring Boot might not be inherently as concurrent as Phoenix, but that matters little compared to the great performance it can deliver – especially if attuned for specific use cases. Its integration with cloud services and support for microservices architecture enables developers to build scalable applications to handle various loads efficiently.
Which to choose between Spring Boot and Phoenix depends on the specific needs of an application. For applications demanding must have real-time capability and high concurrency, Phoenix could be the best choice. On the other hand, applications in need of extensive integrations with existing Java ecosystems would offer more familiar and more flexible answers in Spring Boot.
Development Experience
Spring Boot is approachable by all developers of any experience level because of its ease of use and extensive documentation. With it’s approach of ‘convention over configuration’, it simplifies the development process to build features without having to spend too much time on infrastructure management.
Phoenix demands a different mindset because of its functional programming paradigm, which is definitely bound to making thei learning curve a bit steeper for developers used to object-oriented programming. The same, however, sets them up for writing clean and maintainable code with minimal errors.
Both have extensive tooling and communities that assure a developer that everything will be set for them to make their project a success. The decision between Spring Boot versus Phoenix will come down to your team’s experience with the underlying language and their desire to adopt new paradigms.
Ecosystem and Community Support
Most importantly, whether the framework is suited for long-term projects is going to depend a lot on its ecosystem and support by the community.
Spring Boot is a Java-based ecosystem that further expands upon the rich ecosystem of libraries, tools, and enterprise integrations that java already has. It plays quite nicely with a multitude of mature tools: Spring Cloud for distributed systems, Spring Security for robust authentication, and Spring Data for managing data access layers. Its large and active community means more regular updates, really extensive documentation, and a plethora of third-party plugins to solve nearly any development need.
The Elixir and Erlang ecosystem is younger and smaller in scale compared to the Java ecosystem that Spring Boot relies on. However, it leverages modern tooling: for instance, Ecto for database interactions and LiveView for real-time UI development. This makes Phoenix a really forward-thinking choice for developers. Its smaller developer pool and ecosystem may pose a problem for teams looking for extended pre-built integrations or enterprise-grade support. Additionally, because Phoenix is built on Elixir—a functional language—developers coming from an object-oriented background (like Java) may face a steeper learning curve compared to more familiar frameworks like Spring Boot.
Modern Trends in Spring Boot and Phoenix
Both frameworks are in active development with Spring Boot and Phoenix constantly trying to match demands for modern software development.
Spring Boot is rapidly aligning itself with cloud-native architecture and Kubernetes, offering powerful tools for the rapid deployment and scaling of microservices. Spring Boot 3.0 also leverages GraalVM for improved startup performance, making it well-suited for serverless applications. In addition, its advanced security features and growing integration with AI/ML workflows make it an increasingly strong fit for modern enterprise and distributed system development. Complementary features like Spring WebFlux—supporting reactive programming—further extend its capabilities for teams looking to adopt event-driven or highly asynchronous models. Phoenix is really pushing the boundaries on real-time Web development; for instance, Phoenix LiveView, which enables interactive user interfaces without the use of any JavaScript frameworks. Its high concurrency makes it one of the best options for scalable and fault-tolerant applications. Developments within tooling like Ecto and support for modern databases -such as PostgreSQL with JSON support or NoSQL systems via adapters- ensure it stays a forward-looking choice for distributed and real-time systems. Recent additions like Nx and Bumblebee are opening the door to native AI/ML capabilities within Elixir, enabling real-time inference and model serving directly within Phoenix applications.
Choosing the Right Tool for the Job
Having looked at the strengths and philosophies of both frameworks, it comes down to matching the tool to your project’s specific needs.
The choice between Spring Boot and Phoenix really boils down to what your application requires and the environment in which you’re working. It’s really a matter of selecting the right tool for the job. If something is built on high concurrency, real-time features, or it must be able to handle thousands of simultaneous connections – like a bustling city that never sleeps – then Phoenix is your best option. Its architecture thrives in such dynamic, fast-pacing environments, providing unparalleled performance and reliability.
For projects deeply married to the Java ecosystem, leveraging on existing libraries, or needing any robust form of microservices architecture, Spring Boot is far and away the obvious choice. It’s like calling up an expert who knows just about everything there is to know in an enterprise landscape, fitting into legacy systems and accelerating development timelines.
Beautifully, they don’t compete with each other but complement. Each has its unique strengths that help you understanding which one fits the bill for your project. Whether it’s the precision of a surgeon or the marathon endurance runner, each of these, Spring Boot and Phoenix, can help you craft applications that are robust, scalable, and ready to meet the demands of the future.
Why We Use Both — and How We Choose
At Inspired, we don’t pick frameworks based on trends or team preferences—we choose based on what will serve our clients best in the long run. The real question isn’t which framework is “better,” but which one fits the client’s context, capabilities, and goals. Here’s how that plays out in practice.
Whenever the client does not have a dedicated software development team or is relying on us to deliver a fully managed solution, we tend to go for Elixir and Phoenix. It’s a system that’s simple to scale and maintain, making it ideal for clients who want long-term stability without having to build out a large in-house engineering team. That’s why Phoenix is our default when we’re given full ownership of the solution.
On the other hand, when we anticipate the client will eventually take over development—either by building their own team or integrating with an existing Java-based stack—we lean toward Java and Spring Boot. The broader talent pool, rich ecosystem, and familiarity of the Java world make it easier for those teams to pick up and run with the software once we hand it off. Additionally, Spring Boot is often the better choice in enterprise contexts where integration with legacy systems or compliance requirements is a concern—areas where the Java ecosystem has decades of maturity and tooling behind it.
In both cases, the goal is the same: to set our clients up for success, whether they’re leaning on us for the long haul or preparing to take the reins themselves.
Christian Albrecht
Christian ist einer der Gründer von Inspired und arbeitet seit über 25 Jahren in der Softwarebranche. Er hilft Teams und Organisationen dabei, komplexe Software-Ideen in solide, praxisnahe Lösungen zu verwandeln – technisch, organisatorisch und immer mit Blick auf die Menschen.
Manchmal schreibt er Code, manchmal moderiert er Workshops – und oft fungiert er als Brücke zwischen Produktvision und technischer Umsetzung. Er ist auch der Autor des Architekturreview Workbooks.
