NAFDAC-certified agro-processing ecommerce platform with integrated B2B and admin operations
Stack
GoNext.jsTypeScriptPostgreSQLPaystackRailway
Overview
A full-stack ecommerce platform built for a Nigerian NAFDAC-certified agro-processing brand, combining a direct-to-consumer store with a B2B inquiry system and a role-gated staff admin panel. Covers the full commerce surface: product catalog, cart, guest and authenticated checkout, Paystack payment integration, order lifecycle management including delivery confirmation and manual-confirmation handling for live-animal pre-orders, and inventory tracking. Runs as a pnpm monorepo with a custom Go REST API and two Next.js frontends sharing a component library and OpenAPI-generated TypeScript types.
Challenge
Payment correctness was the highest-stakes surface: Paystack webhooks needed HMAC-SHA512 verification plus reference-based idempotency so a retried or duplicated webhook could never double-fulfill an order, paired with a client-generated idempotency key to stop duplicate submissions from flaky mobile networks. The same correctness concern applied to inventory - per-variant stock lived in a JSONB column, and a naive read-modify-write under concurrent checkouts would lose updates, so stock mutations were rewritten around Postgres's jsonb_set to update atomically instead.
Outcome
Shipped as a complete two-frontend system: a customer store and staff admin panel sharing a single root-domain auth cookie with role-based route protection built on Next.js 16's proxy.ts, a transactional guest-to-account order claim flow that retroactively attaches guest orders on account creation, and a Postgres integration test suite via testcontainers-go alongside Vitest/RTL and Playwright E2E coverage across both apps.
