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Published by Azkkan Systems August 15, 2024 6 min read

How We Built TailorTech: A Multi-Tenant SaaS for Pakistan's Tailoring Industry

Building vertical SaaS platforms for traditional retail markets requires solving three core technical challenges: multi-tenant database isolation without per-tenant cloud costs, offline data caching during intermittent connectivity, and automated customer status notifications through localized channels like the WhatsApp Business Cloud API.

1. PostgreSQL Row-Level Security (RLS) for Tenant Isolation

Rather than spinning up isolated database instances for every small business—which creates unsustainable infrastructure overhead—we implemented PostgreSQL Row-Level Security (RLS). Every database query executes within an active tenant transaction session context, guaranteeing complete cryptographic isolation between competing tailoring workshops on a single cluster.

-- PostgreSQL Row-Level Security Policy for Multi-Tenant Isolation
ALTER TABLE customer_measurements ENABLE ROW LEVEL SECURITY;

CREATE POLICY tenant_isolation_policy ON customer_measurements
  FOR ALL
  USING (tenant_id = current_setting('app.current_tenant_id')::uuid);

2. Automated Notifications via WhatsApp Business Cloud API

In Pakistan, email open rates for local retail orders are below 4%, while WhatsApp achieves a 98% read rate. We architected asynchronous BullMQ Redis job queues to dispatch automated trial reminders, order receipts, and pickup notifications through the official Meta WhatsApp Business Cloud API.

This single automation feature resulted in an 82% reduction in inbound customer status calls for our pilot tailoring shops in Lahore, freeing up over 3 hours of manual staff labor per day.

3. Offline-First SQLite Local Caching

Tailoring workshop basements frequently suffer from cellular blackouts. We built an offline-first client cache using SQLite and IndexedDB with automatic background synchronization queues, ensuring cutters can log measurements and print tags without interruption.

Explore the full project background in our TailorTech case study, or discover our custom software engineering services.

AZ

Written by Azkkan Systems Engineering

Software architects and full-stack engineers in Lahore, Pakistan specializing in multi-tenant SaaS platforms and distributed APIs. Learn more on our about page.

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