Hisab Sathi — SaaS Accounting for Shopkeepers
Hisab Sathi is a multi-tenant SaaS that replaces paper ledgers for small shopkeepers in Bangladesh. Each shop gets its own isolated business space with phone + OTP login, product & stock management, sales and purchase ledgers, party (customer/supplier) accounts, and expense tracking. The platform runs on PostgreSQL (Supabase) with Prisma 7, Redis for caching, BullMQ workers for SMS/Email/Push/report jobs, Socket.IO for real-time sync, and Cloudflare R2 for document storage — with a plan/quota entitlement engine for subscription billing.
Project Overview
Hisab Sathi is a multi-tenant SaaS that replaces paper ledgers for small shopkeepers in Bangladesh. Each shop gets its own isolated business space with phone + OTP login, product & stock management, sales and purchase ledgers, party (customer/supplier) accounts, and expense tracking. The platform runs on PostgreSQL (Supabase) with Prisma 7, Redis for caching, BullMQ workers for SMS/Email/Push/report jobs, Socket.IO for real-time sync, and Cloudflare R2 for document storage — with a plan/quota entitlement engine for subscription billing.
The Challenge
- Shopkeepers tracked sales, dues and stock in paper notebooks — end-of-day totals were guesses, and money leaked silently.
- A multi-tenant system must guarantee that one shop can never see another shop's data — isolation had to be enforced at every layer.
- Shop owners use cheap Android phones with unstable internet — the app had to stay fast and never lose a record.
- OTP-based login for non-technical users had to be bulletproof against brute-force attempts.
Our Solution
Multi-tenant Architecture
Every request carries a business context — products, sales and ledgers are automatically scoped to the logged-in shop.
Phone + OTP Login
No email, no passwords to forget — shopkeepers log in with just a phone number and an SMS OTP, with lockout protection.
Complete Ledger System
Sales, purchases, parties, dues and expenses — every entry updates stock and balance sheets in real time.
Queues & Realtime Sync
BullMQ workers handle SMS, push and report generation off the main thread, while Socket.IO keeps every device in sync.
The Results
Multi-tenant
One platform, unlimited shops
< 30s
From phone number to dashboard
4
Background job queues running
Zero
Cross-shop data leaks