Installment & Retail-Credit Operations Platform
A production platform for a retail-credit business: customer portal, staff back office, installment scheduling, automated payment reminders, and role-based access — shipped as an isolated Docker stack with restore-tested backups.
- Year
- 2025 — ongoing
- Role
- Architecture, full-stack build, deployment & operations
- Disciplines
- engineering · commerce · automation
- Stack
- Next.js · TypeScript · PostgreSQL · Docker · Nginx · Certbot
01Context
A retail business extends credit to customers through installment plans. Tracking schedules in spreadsheets made exposure hard to see, and manual follow-up meant reminders went out late — or not at all.
The engagement covered the full path: data model, application, deployment, and the operational runbook around the system.
02What was built
- //Customer-facing portal for schedules, balances, and payment status
- //Staff back office for accounts, installments, adjustments, and collections notes
- //Automated reminder pipeline with auditable delivery logs
- //Role-based access with a hard separation between staff and admin capabilities
- //PostgreSQL with automated nightly dumps that are restore-tested, not just taken
- //Isolated Docker deployment behind its own reverse proxy and TLS certificates
03Engineering decisions
The installment schedule is modeled as derived state from an append-only ledger of charges and payments, so a bug can never silently rewrite history — balances are always recomputable.
Reminder delivery is idempotent: a reminder may be sent late, but never twice for the same due date. Every outbound message is logged against the account for audit.
Staff tooling stays deliberately boring — server-rendered tables, explicit actions, no client-side cleverness where a form will do.
04Status
In production and under continuous development. The client name and all business data are withheld by agreement; the architecture and scope are described faithfully.