There's a kind of electronic circuit known as a filter, whose purpose is to allow only certain frequencies through. If you've ever used an old-school graphic equalizer on a sound system, or even bass and treble knobs, you've been adjusting a filter circuit.
There are approximately a gazillion (plus minus a bazillion) different kinds of filter circuits, but I'm particularly interested in a specific kind of filter, known as an LC Ladder filter, for some of the radio projects I'm noodling around with (None of them have come far enough to be worth putting up on this site yet).
The calculations involved in designing such a filter circuit are onerous enough that I don't want to do them by hand, but they really aren't all that much for a computer to do. There's a variety of online calculators for them out there, but none of them is exactly what I want.
As I said, there isn't all that much arithmetic involved, for a computer, but there are a bunch of parameters to twiddle. All of this makes an in-browser calculator a nice fit for the problem. Because it's in the browser, that makes the language choice simple: JavaScript.
A raw JavaScript application, however, can drive you crazy. It's pretty easy to do simple things, but as you start adding features without an overall framework, you quickly hit a threshold where interactions among the various bits code becomes overwhelming. And you generally hit that threshold without much warning. To deal with that problem, people have been creating application frameworks for in-browser JavaScript for some time. Of the current crop of frameworks, I prefer React.
So, that's the short-form description of the project: An in-browser calculator, written in JavaScript/React, for designing LC ladder filters.