Worked on the frappe/erpnext repository to deliver a targeted reliability fix in the pricing rules module, focusing on backend development with Python. Addressed a None-value handling issue in free item quantity calculations, updating the pricing_rule/utils.py file to ensure transaction_qty calculations no longer fail when encountering missing data. This change improved pricing accuracy and transaction stability, reducing the risk of runtime exceptions in pricing flows and safeguarding revenue calculations. Collaborated with other contributors through Git-based workflows, code reviews, and test-driven debugging. The work enhanced data integrity and user experience by making pricing behavior more predictable and robust within the ERPNext platform.