Java remains a strong choice for new application projects. If starting a new Java project in 2025, platform independence, robustness, a rich library ecosystem, good performance, and strong security are the keywords you are looking for. Let’s take a better look at the decision-making process for a new Java application project.
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1. Team dynamics drive architecture choices
The saying goes that software architecture follows organizational structure. Although often discussed negatively, this can also indicate the most intuitive option. You are not Google, and maybe you should not choose the same technical solutions? Instead, take a look at the team and organization you have and start from there.
Netflix" (or someone else) is using that technology will never be a good decision-making approach. Let the requirements command the decision process, focusing on your organization's reality, environment, and culture.
– From the report: “Key Considerations for New Java Projects in 2025”
Indeed. A software architecture decision should start by looking at the people who will build and maintain the system. A typical development team often includes a mix of senior and junior developers, possibly with a tech lead or architect guiding them.
A full-stack team is more agile, while a front-end/back-end split allows for deeper expertise.
– From the report: “Key Considerations for New Java Projects in 2025”
The structure, competence, and experience of this team should heavily influence the chosen architecture. In practice, simpler architectures tend to succeed when team experience is limited or spread thin, whereas very complex, distributed architectures demand more specialist skills.
2. Choosing the right Java and JRE version
With team considerations in mind, the next key decision is the technology stack itself, starting with the Java version and JVM. In 2025, the Java ecosystem has evolved significantly, and sticking with older versions means missing out on productivity and performance gains.
For most new projects, using the latest Long-Term Support (LTS) Java release is advisable. As of now, Java 21 is the current LTS, and it brings features that can actually simplify your architecture and code. A headline feature is virtual threads stabilized in Java 21. Virtual threads are lightweight threads managed by the JVM, allowing you to create thousands (even millions) of concurrent threads with minimal OS overhead.
When choosing your Java version, also consider the support timeline and ecosystem compatibility. Java 17 was the previous LTS and is still a common choice for many enterprises in 2025. If your team relies on frameworks or application servers that haven’t caught up to Java 21, Java 17 is a solid fallback. However, if starting fresh, leaning into Java 21 is wise – it ensures your application’s lifespan aligns with a long support window and that you can take advantage of the latest features like virtual threads, record classes, text blocks, pattern matching, etc.
On the other hand, if you know that the project will be in development for a long time, it makes sense to aim for the next LTS and use the latest release until then. The new features not only improve developer ergonomics but can also reduce the amount of third-party libraries you need, which brings us to the next topic.
Find more Java expert insights inside the report: “Key Considerations for New Java Projects in 2025.” Get your copy!
3. Use what Java (or the JVM platform) gives you out of the box
This philosophy also extends to staying within the Java/JVM ecosystem for as much of the stack as makes sense, especially if your team is primarily Java-skilled. A good rule of thumb: first, try to solve the problem with core Java or a proven standard library.
For instance, do you need JSON processing? The Java EE/Jakarta API offers JSON-P and JSON-B, and if you need more, a single dependency on Jackson or Gson is fine – but you probably don’t need a whole more than that just for transformation. Need to schedule background tasks? The JDK’s ScheduledExecutorService or even java.util.Timer might be enough, rather than introducing a full-blown messaging system or Quartz scheduler in a simple app.
By leaning on the stability and performance of the JVM itself, you also avoid version mismatches and framework lock-in. This will also benefit the operations when going to production and entering maintenance mode.
4. Deployment and scalability: Keep it simple
When it comes to long-term maintainability, simple deployments shine. Fewer moving parts means fewer integration failure points. A single full-stack app can be rolled back or updated in one go, without complex coordination of dependent service versioning. You also avoid the scenario of one microservice failing and causing confusing partial outages – in a monolith, either the whole app is up or it’s down (and if down, all hands go to one place to fix it).
Evaluate managed services (e.g., GKE, EKS, AKS) for reduced operational overhead, check for strong community support and documentation, ensure robust security features, and consider cost transparency. Test for seamless integration with your CI/CD pipelines and monitor performance to align with your long-term goals.
– From the report: “Key Considerations for New Java Projects in 2025”
Logging and tracing are straightforward (one app = one log context). Furthermore, security and compliance are easier with a smaller attack surface (e.g., one entry point to secure, rather than many services calling each other).
This is not to dismiss the genuine advantages of microservices for certain cases (like independently scaling hot spots, isolating failures, or enabling polyglot development). But advantages only outweigh the costs if you truly need them. In many cases, a thoughtfully designed monolith can achieve high reliability and scalability.
Again, your organization and team structure might give you a sign, which is the architecture.
5. Total cost of ownership and lifespan considerations
Long-term maintainability also benefits from starting simple. You are building a successful application, and you might be maintaining it for 5, 10, or more years. (Not you personally, of course, but someone will, and they appreciate a legacy instead of technical debt.)
Over such a period, staff will turn over and technologies will evolve. Choosing stable, well-understood tech now sets you up for easier maintenance later. Java as a platform is known for its strong backward compatibility – code written today on Java 21 can likely still run with minimal changes on Java 25 or 29 in the future. Similarly, frameworks with proven history tend to stick around with active support.
The support timeline of your stack components in your TCO, if you pick Java 21 (LTS) and perhaps a stable framework, you know you’ll get patches and updates for many years. Keep an eye on the release cadence of the tools that you choose – new Java LTS versions come roughly every two years now, and you might plan maybe a mid-lifecycle upgrade (say Java 25 in the future) to keep things fresh.
Still unsure about the future?
When in doubt, choose the architecture that minimizes complexity and maximizes the productivity of your existing team. In today’s Java landscape, that often means a full-stack, monolithic application as the starting point. This is where Vaadin also stands: architectural simplicity empowers teams to scale based on their own resources.
This aligns with the competencies of a typical Java team, reduces the need for cross-team coordination, and avoids the many pitfalls of premature modularization. By keeping front-end, back-end, and even database concerns in one cohesive project (or at least one coordinated team), you reduce the communication overhead and hand-off delays that often plague projects where every layer is handled by a separate group. This can save over 12% of total working time.
As a general rule of thumb: If you’re unsure about the path forward, deliver value. Grow the application, and re-evaluate as needed. Chances are, you’ll find that straightforward architecture carries you a long way, and you can build your success on top of earlier success.
If you need more data to back up your decisions, our report “Key Considerations for New Java Projects in 2025,” which offers 123 pages of practical insights from Java experts in the field, will come in handy. Good luck and build for happy users!