WhatsApp-native POS super-app with invoice trust loop for emerging markets.
Ojanaa is a production-grade transaction platform that solves trust problems in informal commerce. Merchants create invoices via mobile app, customers receive and pay via WhatsApp, and both parties receive cryptographic proof of every transaction.
Invoice Trust Loop: Invoice → Payment → Confirmation → Receipt
Every state transition creates verifiable evidence. Both parties get proof at each step.
- Small merchants can't afford traditional POS systems
- Informal transactions lack receipts and proof
- Customers dispute payments with no recourse
- Trust is low, sales are lost
| Layer | Technology |
|---|---|
| Mobile | React Native, Expo |
| Web | Next.js App Router |
| Database | PostgreSQL, Supabase |
| Messaging | WhatsApp Business API |
| Payments | Mobile Money, Cards |
- Single backend surface — no separate API service, reduced operational complexity
- Row-Level Security on all tables — database-level organization isolation
- Idempotent webhook handlers — safe retries for payment and messaging events
- Phase-gated development — no Phase 2 until Phase 1 passes quality gates
See ADR index for detailed decision records.
| Document | Description |
|---|---|
| Architecture | System design and components |
| Case Study | Full project overview |
| Security | Security posture and practices |
| ADRs | Architecture decision records |
| Runbooks | Operational procedures |
The core implementation is in a private repository to protect intellectual property and business logic. This repository contains architecture documentation, engineering decision records, operational runbooks, and demo materials.
For code samples or technical discussions: LinkedIn
- Portfolio — all case studies and architecture samples
- Case Study — full project deep-dive