etrotta

Would an experienced Java developer that has never touched JavaScript before know how to use JavaScript well enough to use it in a professional application without having to learn/revise a lot of things?

Would an experienced JavaScript developer that has never touched Java before know how to use Java well enough to use it in a professional application without having to learn/revise a lot of things?

No and No - They are like car and carpet. Unlike something like C and C++ or JavaScript and TypeScript that you can easily adapt to in a relatively small amount of time, Java and JavaScript serve completely different use cases and require significantly different skillsets.

Like others said, definitely consider using Jupyter Notebooks for development (note: not necessarily JupyterLab, just Notebooks - multiple IDEs like VSCode support them).

For an actual GUI, I would recommend considering some web dashboard frameworks like Streamlit, Dash or Gradio if you are not felling like spending too much time organizing the layout and making it pretty.

Other than that, I would also recommend taking a look at a few plotting libraries other than matplotlib like Bokeh or Plotly.