Full-stack · Client engineering
Alpha-Pins
Full-stack delivery from UI to backend reconstruction, including payment gateway integrations (Seerbit, Interswitch, Korapay, Cryptomus).
- Role
- Full-stack Developer (freelance)
- Type
- Client engineering
- Status
- Live
- Stack
- Laravel · React · Vite · TypeScript
1 · The problem
A live product needed reconstruction: a coherent frontend experience on top of a backend that had to be rebuilt without breaking paying flows — including multiple payment gateways.
2 · My responsibility
Full-stack freelancer — UI implementation through backend reconstruction, gateway integrations, and end-to-end delivery.
3 · The architecture
Laravel backend with React/Vite frontend; payment processing abstracted behind one interface with per-gateway adapters (Seerbit, Interswitch, Korapay, Cryptomus); staged rollout behind the existing domain.
4 · Key engineering decisions
Adapter pattern for gateways so a provider outage or API change touches one file; rebuild behind the live system rather than a big-bang rewrite; staging environment mirroring production config.
5 · The hardest problem
Four gateways, four failure modes, one checkout. Solved with idempotency keys, webhook verification per provider, and a reconciliation pass that catches anything the callbacks miss.
6 · What I would improve
Centralized payment observability — one dashboard for success rates and latency per gateway — so integration health is visible instead of inferred.