01
Modular NestJS Backend & Relational Schema
Architected NestJS service modules for inventory, billing, users, and RBAC permissions. Designed normalized PostgreSQL tables with transaction blocks so stock counts stay accurate.
./Enterprise Systems/Full-Stack System Architect
A modular NestJS ERP platform with automated WhatsApp, Meta Catalog, and Drive workflows.
Centralizing core business operations while automating WhatsApp messaging via WATI, daily catalog syncing through Meta Business API, Google Drive image uploads, and Instagram publishing with Publer.
- My Role
- Full-Stack Lead Architect & Integrations
- Focus
- NestJS, Next.js, PostgreSQL, WATI, Meta Graph API, Google Drive & Publer APIs
- Project Type
- Enterprise ERP & Automation
- Timeline
- Full Implementation
WhatsApp Catalog Sync
Daily Auto-Sync
Customer Alerts
Real-time via WATI
API Response Time
<80ms
Data Integrity
100% ACID
[01] The Challenge
Operational bottlenecks & constraints.
Organizing inventory, billing, and order workflows into maintainable NestJS modules without data conflicts during concurrent transactions.
Triggering transactional WhatsApp alerts via WATI reliably on order milestones without blocking dashboard HTTP responses.
Keeping hundreds of product items, images, and prices dynamically synced to the WhatsApp Commerce catalog every single day via Meta's Business API.
Uploading product and resource images directly to organized Google Drive folders via API and scheduling Instagram posts/stories through Publer with clean error handling.
[02] Engineering Contribution
Key architectural breakthroughs delivered.
02
WATI WhatsApp Message Automation
Integrated WATI's REST APIs to automatically dispatch templated WhatsApp messages to customers when orders are confirmed, dispatched, or pending payment.
03
Daily WhatsApp Catalog Sync via Meta API
Built a daily cron job that fetches updated inventory, pricing, and product images from PostgreSQL and syncs them directly into the WhatsApp Commerce Catalog using the Facebook Business / Meta Graph API.
04
Google Drive API for Image Uploads
Integrated the Google Drive API to upload product and resource images directly into designated Drive folders, returning secure image URLs to display across product and project records.
05
Publer API for Instagram Publishing
Integrated Publer's API to let staff schedule and publish feed posts and stories directly to Instagram from the ERP dashboard, keeping product promotions aligned with current stock.
[04] Systems Architecture
Data flow & service topology.
01.NestJS backend with TypeScript decorators, DTO validation, and modular services
02.PostgreSQL relational database with ACID transaction safety and index optimizations
03.React & Next.js dashboard with role-based access control (RBAC)
04.WATI REST API client for event-driven WhatsApp messaging
05.Meta Graph / Facebook Business API background worker for daily WhatsApp catalog sync
06.Google Drive API integration for product and resource image uploads
07.Publer API service for Instagram post and story scheduling
[05] Delivered Artifacts
- Scalable NestJS API backend with clean modular architecture
- Next.js administrative web portal for operations, billing, and social tools
- Event-driven WATI WhatsApp notification system for customer updates
- Daily automated cron job syncing warehouse inventory to WhatsApp Catalog via Meta API
- Google Drive image upload pipeline with organized folder structures
- Instagram post and story publishing module powered by Publer API
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