How to Build a Custom ERP Module Using the MERN Stack With Full Data Integrity

A technical guide published on DEV Community outlines how to build a custom purchasing and inventory ERP module using the MERN stack (MongoDB, Express, React, Node.js). The article focuses on three core concerns: data modeling, consistent multi-document writes, and audit trails for financial accuracy. It recommends embedding line items within purchase orders while referencing independent entities like suppliers and products, and advises storing monetary values as integers to avoid JavaScript floating-point rounding errors. MongoDB's multi-document transactions are highlighted as essential for atomic operations such as receiving goods, where stock levels and order statuses must update simultaneously or not at all. The guide also covers optimistic concurrency control and strategic indexing to support real-world procurement query patterns from day one.