During November 2025, this developer enhanced the SlnkoEnergy/bacKendSlnko backend by building a bill deletion feature that synchronizes total billed amounts and counts on related purchase orders, directly improving data integrity and financial accuracy. Using JavaScript, Node.js, and Mongoose, they addressed a precision bug in the loan creation workflow, ensuring only relevant incoming documents are added to the saved documents list, which prevents misattribution and supports accurate loan document management. Their work demonstrated a strong grasp of backend development principles, with clear commit messages and targeted fixes that reduce data drift and simplify future audits and maintenance for the repository.