Creating Runway

One of the things I really wanted to do was understand my financial situation before diving into what I’m working on now. My first attempt was a Google spreadsheet where I manually calculated how many months I had left based on my savings and expenses.

But I also wanted something a bit more interactive. I didn’t want to keep tweaking formulas every time I spent money or made a bit of income. I wanted a tool that gave me a clear snapshot of where I stood, something I could revisit regularly without friction.

At the same time, I had another goal in mind. I hadn’t touched Rails in about two years, and I missed it. I wanted to get reacquainted with modern Rails and see what had changed since I last used it. I didn’t want to rely on a frontend-heavy setup or bring in a JavaScript framework unless I really needed to. So I kept things minimal and went with Rails 8, using StimulusJS for just enough interactivity to make the experience feel smooth.

That’s how Runway came to life.

The core idea is simple. You set your starting balance, define a monthly budget or burn rate, and check in occasionally to log expenses or income. The app then tells you how much time you’ve got left before you run out of cash. It’s a small utility, but one that’s already helped me make better decisions and feel more grounded during a transition period.

This project gave me a chance to rebuild some muscle memory with Rails and ship something useful at the same time. I honestly wasn’t sure if anyone else would need it, but I figured I’d put it out there anyway.

You can try it out here: https://runway.kakiyaga.com