A language-learning app I made 3 years ago, with React+Redux and Node, to learn JS and implement my language-learning method.
This app allowed me to read a book in English and in another language, side by side. Selecting any word or sentence would fetch a translation online and display it, with examples.
I could upload books and see them on different shelves.
It was running (though it took me months and my implementation of the translation fetching process would make the CPU go to XX%). It was my first JS app and it was running!
One day, I looked away for a second, and when I looked back the entire JS landscape had changed. That day, I was enlightened.
Python is the way.