Wisdom DosooSoftware engineer for backend, systems & mobile.

Problem — Creators need to launch campaigns and receive funds transparently; backers need trust + tracking.

Campaign service → payment intents → ledger → webhooks · idempotency keys for double-charge safety

• ✓Idempotency on all money endpoints
• ✓Ledger-first design, not balance mutation
• ✓Webhook reconciliation job for payment drift

Problem — DVLA Tema needed a single source of truth for assets + sensitive driver/vehicle documents with full traceability.

Document service → signed storage refs → Postgres + audit table · role scopes (clerk / supervisor / admin)

• ✓Immutable audit trail table — no updates, append-only
• ✓Strict RBAC scopes per document class
• ✓Normalized asset ↔ document ↔ user graph for reporting

Problem — Ghanaian SMEs needed branded business email and simple voting tools without enterprise cost or complexity.

FastAPI services → Postgres + MongoDB stores · JWT/OAuth2 admin endpoints · Docker + CI/CD deploys

• ✓Separate transactional and document stores by access pattern
• ✓Admin endpoints behind short-lived JWT with scoped roles
• ✓Onboard-first UX — 4 businesses live in week 1

Problem — Post-harvest losses were eating farmers' income — no direct line to buyers, so produce rotted before it ever sold.

Next.js storefront → Express REST APIs → MongoDB · auth, product listings, bidding and transactions

• ✓MongoDB for cloud-based, real-time data that holds up in rural areas
• ✓RESTful APIs for auth, listings, bidding and transactions
• ✓Node.js backend architected for scalability and maintainability