Welcome to the show, I’m your host Martin Fowler. Today we explore how LLMs help build custom tooling like PlantUMLSteps. In the article Building Custom Tooling with LLMs, I show how I used an LLM to generate boilerplate, design syntax, parse step markers in PlantUML, and even wire up a Gradle task and an HTML viewer for step-by-step sequence diagrams. As I explain, “LLMs can handle boilerplate tasks, freeing developers to focus on design and core logic.” Starting with a clean syntax—@step {"name":"User Authentication","newPage":true}—the LLM helped craft a StepParser, manage declarations, create default steps, and add SVG generation. Next, it scaffolded a Gradle task to process .puml files and an HTML viewer with previous and next controls. But generated code must be “reviewed for habitability,” refactored for clarity, and maintained like any other artifact. The result is a powerful collaboration: LLMs accelerate prototyping while developers ensure long-term code quality.
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