Software Modernization Engineer: Java, OpenRewrite & AI

tl;dr: We're looking for a Java developer with Claude Code experience. You'll use AI to build OpenRewrite recipes that modernize outdated Java applications automatically and close known security vulnerabilities. That keeps software running that society relies on every day, and protects it from attacks.

Tired of touching hundreds of files by hand every time you upgrade? A new Java version, a framework switch, a library with a known vulnerability, and in the end you still miss one spot. Then the next application comes along and it all starts over.

Why it matters

A large share of the software that public agencies, companies and people rely on every day runs on Java. Much of it has grown over many years and is stuck on versions and libraries that stopped getting security updates long ago. Every outdated dependency is an open door for attackers. In 2021, Log4Shell showed how quickly a single library can become a global problem. At the same time, there are far too few developers to bring all that code up to date by hand.

That's where we come in. OpenRewrite applies code changes as recipes: automated, traceable and repeatable across entire codebases. Writing those recipes used to take a lot of effort. Claude Code is changing that right now. The agent writes the first draft including tests, you review it, refine it and run the recipe against real customer code. A good recipe doesn't just close a gap in one project. It closes it in every codebase it's applied to.

This is how we modernize our customers' Java applications at XDEV and keep them secure and maintainable for years to come. We're looking for someone who wants to help shape this still-young field with us.

What you'll do

• Analyze our customers' long-lived codebases and figure out what’s outdated and where the security risks are
• Modernize across the board: new Java versions, the move from javax to jakarta, framework and library upgrades, and replacing dependencies with known vulnerabilities
• Have Claude Code write OpenRewrite recipes and matching tests, review the output critically and refine it until it's right
• Combine recipes from the OpenRewrite catalog with your own where the catalog falls short
• Run recipes against real customer code and make sure the result is a clean, reviewable pull request

Sound interesting?

OpenRewrite, Claude Code, Java 8 through 25, Jakarta EE, Spring, Hibernate, JUnit, Lossless Semantic Trees, Refaster templates, CVEs, Git, legacy code, coffee

If you thought "yes" to most of these, this is the right job for you.

What we offer?

• Meaningful work: you make software more secure that many people depend on, and you see the impact of your recipes
• Agile work with a startup feel, backed by the stability of an established company
• Help shape a young field from the start and have a say in how we use AI for modernization
• Work with Claude Code and current models. We provide access.
• Exclusive training, certifications and conference visits, so you learn early what's coming and how to work with it
• Flat hierarchies and transparent communication
• Learn more about how we work at XDEV here
  

Your profile

• At least 2 years of professional experience in Java development
• You already work with Claude Code and know how to give the agent the right context, review its output critically and steer it in the right direction
• Experience with upgrades and migrations in long-lived Java applications, whether Java versions, frameworks or libraries
• Security isn't a side topic for you. Outdated dependencies and open CVEs bother you.
• You enjoy writing not just code, but code that changes code
• Testing isn't a chore: a recipe is only done when the tests show it does what it should
• Some experience with OpenRewrite is a plus. You'll learn the rest with us.
• You're a team player and work reliably, independently and with commitment

Right from the first day, we make every effort with our onboarding program to ensure that possible hurdles are removed and that you have a good start at XDEV by all accounts.

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