BUY'N'/SELLEM.
Buy'N'Sellem wanted a classifieds marketplace designed for Cameroon — not a copy of a Western template. Location-based search by city, prices in XAF, direct buyer-to-seller negotiation, and a mobile app that works on slow networks.
Challenge: Ship a website and a native mobile app at the same time, sharing one API, one data model and one set of business rules — without duplicating code across the two platforms.
Scoping & data model
Weeks 1-3
Design system & mockups
Weeks 4-7
Web + mobile in parallel
Weeks 8-13
Real-time chat & go-live
Weeks 14-16
Figure published by the platform.
A living catalogue, moderated continuously.
Douala, Yaoundé, Dschang, Bafoussam…
Web and mobile on a shared foundation.
The interface delivered.
Fig 1.0 — buynsellem.com, in production.
The colour system.
Flows & screens.
Tech
Sheet.
Deliverables
What it changed.
One foundation, two platforms
The monorepo's four shared libraries — API client, types, hooks and utility functions — are consumed identically by web and mobile. A change to the listing model propagates to both applications without a rewrite.
Real time without a heavy back end
Rather than maintaining a socket server, messaging runs on Firestore. Conversations sync instantly between web and mobile, and the infrastructure stays down to one Directus CMS and one Firebase project.
Project credits.
