Rethink3D — a 3D printing marketplace in your pocket

The problem

People in São Luís who need a 3D printed part don’t know who prints, how much it costs or how to send the file. People who own printers have no storefront.

What I built

I’m a co-founder of Rethink3D and the lead developer of the app (630 of the repository’s 893 commits, Dec 2024 to Oct 2026). In the app:

• customers upload a model (STL, 3MF) or ask someone to model it from an idea;
• they get quotes from Makers and negotiate over chat — text, photos, audio, video and location;
• they pay with Pix and track the order status;
• Makers set up a storefront, manage orders and get paid after delivery.

Decisions

Expo with over-the-air updates. Fixes reach phones through EAS Update, per channel (preview and production), without waiting for store review.

File-based routing. The 44 screens follow Expo Router’s folder structure, with universal links that open the app straight on a product.

By the numbers

• 630 of 893 commits on the app
• 44 screens
• live on the App Store and Google Play (50+ downloads on Google Play)