Staring at an old Java codebase that has thousands of lines, outdated APIs, and confusing logic can feel overwhelming. But what if, instead of feeling stuck, you had an AI tool that actually understands the code?

That’s what IBM watsonx Code Assistant does. It reads your code like an experienced developer, explains what it does, and even suggests ways to modernize it.

It’s more than just a code generator. It's like having an AI teammate built for complex modernization work.

In this overview, you’ll see how IBM watsonx Code Assistant can speed up your workflow, simplify tough projects, and help you work smarter with legacy systems. You can even try it out yourself with our interactive product tour.

Quickly understand large codebases

Joined a new team and inherited a huge application with no documentation? You’re not alone. IBM watsonx Code Assistant is here to help.

It breaks down complex, messy code with three explanation modes, so you can choose how much detail you need:

• Simple mode: Shows the business purpose and a high-level summary

• Detailed mode: Explains specific function logic

• Guided mode: Walks you through the code step-by-step

It’s not just for Java, either. It also supports Go, C, C++, JavaScript, Python, and TypeScript. Plus, it works right inside VS Code and Eclipse, so you can keep coding while it helps you make sense of everything.

Let AI take care of the repetitive work

Tired of writing boilerplate code, creating unit tests, or documenting code you didn’t write? IBM watsonx Code Assistant can handle that for you.

It helps you focus on what really matters by offering:

• Code generation for common patterns

• Auto-created unit tests

• AI-powered documentation for easier handoff

• Conversational AI to help write, plan, or refactor code

• Prebuilt chat commands for faster coding tasks

Whether you're starting a new service or updating legacy code, watsonx code Assistant gives you smart support every step of the way.

Modernize legacy Java with confidence

Working with old Java code can be risky. Outdated APIs, old libraries, and tricky workarounds can easily break things.

IBM watsonx Code Assistant helps you modernize safely with smart, guided fixes:

• Replaces deprecated APIs such as ServletChain and Startup Beans Service

• Suggests safer ways to handle things such as PrintStream default charsets

• Guides Java version upgrades with alternatives to removed methods such as defineAnonymousClass

This isn’t just basic find-and-replace. IBM watsonx Code Assistant understands your code and gives helpful, context-aware suggestions to keep everything running smoothly.

Real results from real teams

Teams using IBM watsonx Code Assistant have seen real improvements in their day-to-day work, including:

• Faster development

• Fewer manual errors during modernization

• Less time spent on repetitive coding tasks

• Better understanding of complex legacy code

See how IBM’s own software team used IBM watsonx Code Assistant to boost productivity in this case study.

Try it yourself in an interactive tour

Reading about it is one thing, using it is another.

Take the interactive product tour to see how IBM watsonx Code Assistant fits into your workflow, without installing anything. In the tour, you’ll learn how to:

• Understand code using explanation and documentation tools.

• Boost productivity with code generation and testing.

• Modernize legacy Java with guided, step-by-step help.

Start the tour and see it in action.