Business ERP System

Project Overview

Key Features

• Multi-Warehouse Inventory: Manage inventory across multiple warehouses with stock transfers, stock adjustments, movement history, and real-time stock availability.
• Complete Sales Workflow: Quotation → Sales Order → Invoice → Delivery → Collection with support for partial payments and product returns.
• Purchase Management: Supplier management, purchase workflows, supplier ledgers, payment vouchers, and purchase-related financial tracking.
• Accounting System: Chart of accounts, expenses, account transfers, payment transactions, collections, and running account balances.
• Advanced Reporting: 36 business reports covering sales, purchases, inventory, accounting, payments, suppliers, and operational data with Excel and PDF exports.
• Role-Based Access Control: 128 granular permissions across 15 ERP modules with configurable user roles and access control.
• Transaction-Safe Inventory: PostgreSQL transactions and row-level locking prevent overselling and inventory inconsistencies during concurrent operations.
• Invoice Audit Trail: Tracks invoice modifications field-by-field with the previous value, updated value, user information, timestamp, and required edit reason.
• Controlled Invoice Editing: Invoices remain locked by default while administrators can grant one-time, time-limited permission to a specific user for editing a specific invoice.
• Real-Time Notifications: Socket.IO based real-time notifications and administrative force-logout functionality.
• Export & Document Generation: Business reports and operational documents can be exported to Excel and PDF.

Key Responsibilities

• System Architecture: Designed the complete ERP architecture covering frontend, backend, PostgreSQL database structure, APIs, authentication, permissions, and business workflows.
• Backend Development: Built 227 RESTful API endpoints using Node.js and Express 5 for inventory, sales, purchases, accounting, reporting, users, permissions, and other ERP modules.
• Database Design: Designed and maintained 64 PostgreSQL tables using raw SQL without an ORM for precise control over queries, relationships, transactions, and performance.
• Inventory Integrity: Implemented transaction-based stock operations with PostgreSQL row-level locking to prevent overselling and race conditions during concurrent requests.
• Sales Workflow: Developed the complete quotation, sales order, invoice, delivery, payment collection, and return workflow.
• Purchase & Supplier Management: Implemented purchase operations, supplier accounts, supplier ledgers, payment vouchers, and related financial workflows.
• Accounting Module: Developed chart of accounts, expenses, transfers, collections, payment records, and running balance calculations.
• Reporting System: Developed 36 operational and financial reports with filtering, aggregation, Excel export, and PDF generation.
• RBAC & Security: Implemented 128 granular role-based permissions across 15 application modules.
• Audit & Invoice Security: Built invoice locking, detailed audit trails, edit reasons, and one-time time-limited invoice editing permissions.
• Real-Time Features: Integrated Socket.IO for notifications, application events, and administrative force-logout functionality.
• Frontend Development: Built responsive ERP dashboards, forms, data tables, reports, filters, workflows, and management interfaces using React 19, Tailwind CSS, and TanStack Query.