GreenLight

Waste materials pile up while decorative goods are bought new. GreenLight asked whether recycling and reuse could be a business, not just a slogan — a small, concrete step toward a circular economy. The test we set ourselves was uncomfortable on purpose: would anyone actually pay for décor made from what others throw away?

As the team's technology lead, I built the online store and the system behind it — product catalog, orders and the back office — so a school project could actually sell to real customers rather than just pitch a deck. It's the difference between a slide that says 'we could sell this' and a checkout button that takes real money.

I want to be precise here: GreenLight was a team of five, and I was deputy lead for technology, not the founder. I shaped the idea and owned the whole technical side while teammates led product, sourcing and sales. Learning to own one pillar completely while trusting four other people with theirs was a different skill from running my own project — and just as valuable.

In its first year GreenLight reached 93 customers and more than 150 million VND in revenue — modest numbers I'm careful not to inflate, but real ones, from real orders that had to be packed and shipped. Real customers complain, return things and change their minds; handling that taught more than any hypothetical market ever could.

The venture won second place at Hanoi's student startup-ideas competition and went on to the National Student Startup round — but the recognition I value most is simpler: the store is still live, and people we've never met have bought from it.

GreenLight taught me to connect three things I care about — computer science, real customers and sustainability. Running a business that had to ship real products was a harder, more honest test than any pitch, and it's the reason I now trust systems that survive contact with real users over ideas that only look good on a slide.