Hire Java Developers

Why hire Java Developers through us

• Vetted through technical screening and a practical exercise
• You interview and choose every candidate
• Working hours overlap with your team
• NDA and full IP assignment to your company
• Monthly terms, trial period and free replacement

Roles and seniority

Skills matrix

What great Java Developers look like

Strong Java developers write modern, readable Java, understand the JVM well enough to tune performance, and know the Spring ecosystem deeply. They are comfortable working in large, long-lived codebases, introducing tests and refactoring safely, and they design services that integrate cleanly with the rest of the enterprise.

Questions we ask in technical interviews

• How do virtual threads change concurrency in Java 21?
• How do you tune JPA for performance?
• How would you migrate from Spring Boot 2 to 3?
• How do you design an event-driven service with Kafka?

Typical projects for Java Developers

• Enterprise application development
• Java and Spring upgrades
• Microservices and integration
• Performance tuning

The first 30 days with a new Java developer

Every engagement starts with a short, structured onboarding so you see useful output early and can judge fit quickly. A typical first month looks like this:

1. Week 1 — Orientation

   Builds services with Maven or Gradle, reviews modules, configuration and deployment, and fixes a small bug.

2. Week 2 — Feature

   Delivers a REST endpoint or message consumer with JUnit and integration tests.

3. Week 3 — Upgrade check

   Reports on Java and framework versions, vulnerable dependencies and the path to a current LTS release.

4. Week 4 — Ownership

   Owns a feature through review, deployment and monitoring.

What to look for beyond the CV

Years of experience and a list of technologies say little about how someone works. In our screening and in your interviews, these are the signals that matter most:

• Writes clean, modern Java using records, streams and current language features sensibly
• Understands JVM memory and garbage collection enough to diagnose problems
• Designs transactional boundaries carefully
• Has worked with messaging such as Kafka or RabbitMQ
• Keeps dependencies patched

Java, Spring Boot or something else?

Most new Java services use Spring Boot; see Spring Boot development for project work. If your team is choosing a stack for a new service, our tech stack guide explains the trade-offs.

The Java developer’s toolkit

Red flags when hiring Java developers

• Still writes Java as it was in version 8 — no records, streams used poorly, no understanding of newer language features
• Cannot explain transaction boundaries or what lazy loading does in Hibernate
• Tests only with mocks and has never run integration tests against a real database
• No understanding of thread pools, connection pools or how a Spring Boot service behaves under load
• Avoids reading framework source or documentation when something behaves unexpectedly

A sample brief for a Java engagement

1. System overview

   Services, their responsibilities and how they communicate — REST, messaging or shared databases.

2. Versions and constraints

   Java and Spring versions, application servers, and any regulatory or change-management rules.

3. The work

   New services, feature development, performance tuning, Java version upgrades or a move off Java EE.

4. Environments

   How developers run the system locally, test environments and deployment process.

5. Success measures

   Throughput, latency or reliability goals, or delivery milestones for the first quarter.

For project-based work see Java development, Spring Boot development and microservices development.

Java version upgrades without disruption

Many organisations still run services on older Java versions because upgrades feel risky. An experienced Java developer makes them routine: upgrading build tooling first, running the test suite and integration tests on the new runtime, fixing removed APIs and dependency incompatibilities, then rolling out service by service. Moving to a current LTS release brings security support, better garbage collectors and language features such as virtual threads that can simplify high-concurrency code.

Where Java developers add the most value

Java systems often run critical, high-volume processes — payments, orders, policy administration, logistics. Experienced Java developers add value well beyond new features:

• Breaking large deployments into independently releasable modules or services where it reduces risk
• Replacing fragile batch jobs with event-driven processing using Kafka or similar messaging
• Improving observability so slow requests and errors are traced to the responsible service
• Hardening security: dependency updates, input validation and Spring Security configuration
• Reducing infrastructure cost by tuning memory, connection pools and JVM settings

If your Java work is part of a larger team, a dedicated team may be a better fit than a single hire.

Typical early wins

A Java developer joining an established system often begins by making the code easier and safer to change: containerised local environments with Testcontainers, a faster and more reliable build, upgraded dependencies with known vulnerabilities, and tracing across services so problems can be found quickly. These improvements shorten the time from idea to production for the whole team.

We agree the balance between this groundwork and feature delivery with your engineering lead, and report progress in every sprint review so the value of each improvement is visible to the business.

Larger structural changes are planned separately with clear milestones.

Ways to engage

Rates depend on seniority and engagement length; you receive a written rate card within one business day. Prefer a managed project? See Java development.

Need a different skill set? See every role on Hire Software Developers.