Migrating from Spring Boot to Quarkus: A Real World Guide – Designbeep

In today’s world of software development, there is growing pressure on Java teams to adopt frameworks that meet modern data needs. In view of modern technologies, the focus should be on improving performance levels that are cheaper and scale well in a cloud-native environment.

Switching from Spring Boot to Quarkus is increasingly becoming a practical way to get better boot times, reduce memory usage, and achieve smoother Kubernetes-native deployments without having to build everything from scratch.

This guide will help 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 you may encounter in production projects.

Why consider Quarkus?

Quarkus is a Kubernetes-native Java framework that enables lightning-fast startups, consumes less memory, and supports native GraalVM images.

Quarkus is optimized for the cloud. The design makes it more efficient for microservices, allowing faster boot times and higher memory usage than Spring Boot. Therefore, it provides better density, more scalability and avoids cold start delays in serverless environments.

When comparing a typical Spring Boot service to Quarkus, teams often find that Quarkus boots much faster and consumes less memory when running the same application logic.

When does migration make sense?

We’ve seen Quarkus be popular in many ways, but that doesn’t necessarily mean every Spring Boot app needs to be migrated. Migration becomes crucial when you have clear performance factors such as:

• Moving to the cloud, where you use Kubernetes or serverless platforms that require less boot time and less 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.
• Standardize APIs where your team standardizes MicroProfile/Jakarta EE APIs or other cloud-native design patterns.

You don’t need to move from Spring Boot if your application is stable, the costs are acceptable and there isn’t a strong cloud-native driver, then a migration isn’t really necessary. Preparing for a migration means having high standards to navigate your system cloud-native transformation through software development services.

Key migration strategies

Real-world teams typically take one of three approaches rather than a “big bang” rewrite.

Feather Compatibility Layer: Use Quarkus’ Spring API compatibility extensions (for web, DI, data, etc.) to run much of your existing Spring-style code on Quarkus, then gradually refactor it.

Incremental strangle pattern: Create and rebuild individual services or bounded contexts on Quarkus, while the rest of the system remains on Spring Boot.

Complete refactoring: For smaller services or greenfield modernization, you can rebuild the system using standard JAX-RS, CDI, and MicroProfile, treating Quarkus as a clean cloud-native platform.

Choosing the right path depends on complexity, the team’s familiarity with Jakarta/MicroProfile, and how closely your application is coupled to Spring-specific abstractions.

How a migration usually works in the real world

A real-world migration doesn’t mean teams have to successfully rewrite everything all 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 can be APIs, database access, configuration and security. You first need to decide which parts are easy to move. Typically, teams prefer to move web APIs and configuration as they can be transferred smoothly quite easily.

Prepare your Spring Boot application

Then you need to start the migration process by gaining a clear understanding of what you already have in your hands.

Main preparation steps:

1. Stock Features: Make a list of the different Spring features you use (Web, Data, Security, Scheduling, Actuator, Cloud, Messages, etc.).
2. Mapping to Quarkus capabilities: Identify an equivalent match in Quarkus extensions or MicroProfile specifications (RESTEasy, Hibernate ORM, SmallRye Health, OpenAPI, Messaging, Config, etc.).
3. View non-functional needs: Consider all technical requirements such as tracking requests, health checks, monitoring handling, and how the application is packaged.
4. Strengthen testing: Make sure you have excellent test coverage so you get a clear picture that the application is behaving according to the changes you made to the code, solid unit and integration test coverage to validate the behavior during the migration.

This primary analysis gives you an idea of ​​how it works and the expected changes in the migration process.

Decide when to build native:

Common challenges to be aware of

There are a number of factors to consider when migrating from Spring Boot to Quarkus. We should be aware that Quarkus manages components very differently than Spring Boot. Therefore, you need to thoroughly verify whether your existing bean behavior is in line with your expectations. Some well-known Spring Boot features, such as Actuator endpoints or certain ways to scan the classpath, do not have direct, one-to-one equivalents. You must map these to the appropriate Quarkus modules. It can take longer build times because native builds slow down your Continuous Integration (CI) pipeline. You should spend time optimizing your build process through caching to keep build times fast.

What are the best practices for a smooth transition?

Following these simple principles can ensure a successful transition:

Start step by step: Migrate your API endpoints and basic configuration. This way you can gain confidence after successfully completing this phase.

Migrate using module-by-module method: You should migrate your application into small, testable chunks rather than moving everything entirely.

Prioritize JVM stability: You must first ensure that the application works properly on the standard JVM. Therefore, you don’t need to rush to use native builds (GraalVM).

Prepare your infrastructure: You may need to select container-friendly base images along with caching support to set up your build pipeline to speed up build times.

Check the most important areas in advance: You should carefully evaluate the appropriate Quarkus extensions that suit your database and security needs before you begin migrating the complex components.

Tuning control: Set up monitoring and tracing that checks the overall health of applications and their functionality using native Quarkus features such as health checks and Micrometer for statistics.

Conclusion

Migrating from Spring Boot to Quarkus may not be a total rewrite, but is actually a performance upgrade. This allows you to maintain your core application logic while achieving lightning-fast startups, significantly reducing memory usage. Therefore, it offers better cloud efficiency. The benefits of Quarkus are related to specialized benefits IIoT platforms that leverage high performance, cost savings and cloud-native efficiency. This shift will deliver massive cost savings, ultimately enabling faster scaling on platforms like Kubernetes.

Author biography

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 of digital transformation trends and regularly explores how emerging technologies such as 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.