Multi-Branch POS & Inventory System

Project Overview

A retail management platform supporting multiple branches with separate stock ledgers while allowing centralized management and reporting. The system covers the full retail operations workflow — from stock arrival and supplier management through daily sales and cashier shifts to management-level reporting across all branches.

Problem

Each branch must maintain its own inventory and sales operations independently so that stock movements, adjustments, and sales at one branch do not affect or interfere with another. At the same time, management needs consolidated visibility across all branches — total stock positions, cross-branch sales, expenses, and performance comparisons — without having to switch between separate systems. Standard single-inventory systems do not support this model cleanly.

My Role

I was responsible for system architecture, backend workflow design, branch-aware inventory logic, RBAC planning and implementation, transaction flow design, audit logging architecture, and the reporting layer design.

Technical Approach

• Branch-aware authentication and access control — users authenticate into a specific branch context
• Branch-specific inventory ledgers with isolated stock balances per branch
• Stock movement tracking: purchases in, sales out, manual adjustments, inter-branch visibility
• Sales transaction workflows covering standard sales, discounts, and receipt generation
• Purchase and supplier management per branch
• Returns processing with stock reconciliation
• Expense tracking per branch
• Cashier shift management with shift open/close workflows and shift history
• Audit logs capturing state changes with timestamps and operator identity
• Role and permission control distinguishing cashier, branch manager, and admin-level access
• Consolidated reporting aggregating data across branches for management view

Core Architecture

The backend is structured around branch isolation as a first-class concept. Each inventory, sales, and financial record carries a branch identifier, and all queries are scoped by branch context at the data layer rather than relying on application-level filtering alone. The RBAC model maps roles to both permissions and branch scope — a cashier can only act within their assigned branch, while a management role can query across branches. Audit logs are append-only and capture the actor, action, and affected records.

Key Engineering Challenge

The main engineering challenge is maintaining correct stock balances per branch while supporting consolidated reporting. Branch-level operations must be atomic — a sale must atomically decrement stock and create a transaction record — while management queries must aggregate across branches consistently without locking branch-level operations. Getting this balance right at the data layer is the core design constraint.

Technologies

Outcome / What the System Enables

The system enables retail operations across multiple branches from a single platform. Branch staff operate entirely within their own context with no risk of cross-branch data contamination, while management has real-time consolidated visibility. The audit log design provides a reliable operations trail. The RBAC model supports the full staff hierarchy without requiring separate deployments per branch.