In the present world of software development, there is a growing pressure for Java teams to adopt frameworks that meet modern data needs. Keeping in mind modern technologies, the focus should be on enhancing the performance levels that run cheaper, and scale well in a cloud-native environment.
Switching from Spring Boot to Quarkus is increasingly becoming a practical way to get better startup times, use less memory footprint, and smoother Kubernetes-native deployments without the need for building everything from scratch.
This guide helps you understand the relevance of moving a real Spring Boot application to Quarkus. At the end, you will also learn about the practical steps, patterns, and pitfalls that you may face in production projects.
Why consider Quarkus?
Quarkus is a Kubernetes-native Java framework that enables lightning-fast startups and consumes less memory, offering support for GraalVM native images.
Quarkus is optimized for the cloud. Its design makes it more efficient for microservices, enabling faster start up times and more memory usage than Spring Boot. Hence, it offers better density, more scaling, and prevents the cold start delay in serverless environments.
If we compare a typical Spring Boot service with that of Quarkus, it is often opined by teams that Quarkus starts up much faster along with less memory consumption when running the same application logic.
When does migration make sense?
We have seen that Quarkus is trending in a lot many ways, but that does not necessarily mean that every Spring Boot app should be migrated. Migration becomes crucial when you have clear performance drivers such as:
- Moving to the cloud where you are adopting Kubernetes or serverless platforms that require less startup time and lower memory is critical.
- Reduce infrastructure costs by running more services on fewer nodes.
- Modernizing legacy Spring Boot 1.x/2.x services that already require refactoring or upgrades.
- Standardizing APIs where your team is standardizing MicroProfile/Jakarta EE APIs or other cloud-native design patterns.
You need not make a shift from Spring Boot if your application is stable, cost is acceptable, and there is no strong cloud-native driver then a migration is not really necessary. Preparing for a migration would entail adopting high standards to navigate your cloud-native transformation through software development services.
Key migration strategies
Real-world teams usually adopt one of three approaches instead of a “big bang” rewrite.
Spring compatibility layer: Use Quarkus’s Spring API compatibility extensions (for web, DI, data, etc.) to run much of your existing Spring-style code on Quarkus, then refactor gradually.
Incremental strangler pattern: Carve out individual services or bounded contexts and rebuild them on Quarkus while the rest of the system stays on Spring Boot.
Full refactor: For smaller services or greenfield modernization, rebuild using standard JAX-RS, CDI, and MicroProfile, treating Quarkus as a clean-slate cloud-native platform.
Choosing the right path depends on complexity, team familiarity with Jakarta/MicroProfile, and how tightly your application is coupled to Spring-specific abstractions.
How a real-world migration usually works
A real-world migration does not imply that teams need to successfully rewrite everything at once. Instead, they follow a simple, step-by-step path:
Evaluate your current app requirements
Make a list of the pieces that matter most. It could be APIs, database access, configuration, and security. You need to decide first which parts are easy to move. Most often teams prefer to move web APIs and configuration because they are fairly easy to transfer smoothly.
Preparing your Spring Boot application
Then you need to start with the migration process by getting a clear understanding of what you already have in your hands.
Key preparation steps:
- Inventory features: Make a list of the various Spring features you use (Web, Data, Security, Scheduling, Actuator, Cloud, Messaging, etc.).
- Map to Quarkus capabilities: Identify an equivalent match in Quarkus extensions or MicroProfile specs (RESTEasy, Hibernate ORM, SmallRye Health, OpenAPI, Messaging, Config, etc.).
- Review non-functional needs: Note all technical requirements like tracking requests, health checks, handling monitoring, and how the application is packaged.
- Strengthen tests: Ensure that you have an excellent test coverage so that you get a clear picture that the application behaves in accordance with the changes you made in the code, solid unit and integration test coverage to validate behavior during migration.
This primary analysis will give you an idea of its working and the anticipated changes in the migration process.
Decide when to build native:
Common challenges to watch for
There are a set of factors that you need to keep in mind while migrating from Spring Boot to Quarkus. We need to be aware that Quarkus manages the components quite differently when compared to Spring Boot. Therefore, you need to thoroughly verify whether your existing bean behavior works in tandem with your expectations. Some familiar Spring Boot features, like Actuator endpoints or certain ways of scanning the class path, don’t have direct, one-to-one equivalents. You’ll need to map these to the appropriate Quarkus modules. It could take longer build times as native builds slow down your Continuous Integration (CI) pipeline. You’ll need to spend time optimizing your build process by caching to keep build times fast.
What are the best practices for a smooth transition?
Following these simple principles will help ensure a successful transition:
Start one step at a time: Migrate your API endpoints and basic configuration. In this way, you can gain confidence after successfully completing this stage.
Migrate using module by module method: You need to migrate your application into small, testable pieces rather than moving everything altogether.
Prioritize JVM Stability: You need to ensure that the application works well on the standard JVM first. Therefore, you needn’t rush to use native builds (GraalVM).
Prepare Your Infrastructure: You may have to select container-friendly base images along with caching support to set up your build pipeline to fasten the build times.
Pre-check Key Areas: You need to carefully review the appropriate Quarkus extensions that are suited for your database and security needs before you start migrating the complex parts.
Tune Monitoring: Set up monitoring and tracing that checks application overall status, its functionality using native Quarkus features like health checks and Micrometer for metrics.
Conclusion
Migrating from Spring Boot to Quarkus may not be a total rewriting but in fact a performance upgrade. Using this, you can keep your core application logic at the same time attaining lightning-fast startups, significantly lowering memory usage. Therefore, it offers better cloud efficiency. The benefits of Quarkus co-relate with specialized IIoT platforms leveraging high performance, cost savings, and cloud-native efficiency. This shift provides immense cost savings, ultimately enabling faster scaling on platforms like Kubernetes.
Author Bio
Sarah Abraham is a technology enthusiast and seasoned writer with a keen interest in transforming complex systems into smart, connected solutions. She has deep knowledge in digital transformation trends and frequently explores how emerging technologies like AI, edge computing, and 5G—intersect with IoT to shape the future of innovation. When she’s not writing or consulting, she’s tinkering with the latest connected devices or the evolving IoT landscape.
