AppMap is an open source VSCode extension which helps you improve your code by showing you how it really behaves, feature by feature, as you work. It does this by automatically generating beautiful, interactive maps of architecture and code behavior right in your editor.
This 2 ¹/₂ minute video, made by the talented (but mysterious) @appmapjava, shows how install the AppMap extension, how to configure it to map your Java code, and how to navigate your code using the interactive diagrams.
It uses the Spring Pet Clinic as an example program.
For full usage instructions, check out appmap-java on GitHub.