We’re a team of developers and cyclists. We met at a hackathon when Eu-wen pitched an idea for a bicycle helmet with a brake light and turn signals. We bonded over the idea and started working on the helmet that same day (we actually won the hackathon with the prototype we built that Sunday afternoon).

We didn’t want that to be the end of the idea, so after a lot more work refining the prototype and validating the idea with cyclists, we took the plunge and started working on Lumos full...