K+ Digital Banking — Backend Services
Digital banking for individuals and household businesses — KienlongBank
Overview
K+ is KienlongBank's retail digital-banking ecosystem. I worked there as a backend developer on three core services covering three business areas: account linking for household businesses (HKD) with a maker–approver step, integration with the HILO partner for e-invoicing, and reconciliation reports for IBFT/NAPAS interbank transactions. The work followed the bank's established architecture and included moving linking data from the old admin system into a dedicated customer-profile service.
Problem Statement
Working inside a live banking system meant some data lived in the wrong place, and partner integrations could not slow down customer transactions. Three problems stood out: moving organisation account-linking data from the old admin system to the new profile service without interrupting the approval process; reliably syncing shop, staff and service-plan data to the HILO e-invoice partner only after a transaction is saved; and exporting large IBFT/NAPAS reports (up to 100,000 records) protected by password and watermark.
UserInterface
My Process
Organisation account linking & data migration
Built the full set of functions to create, view, update the status of and review the history of organisation account links, with 9 processing states and a maker–approver step. Then led the move of that data from the old admin system to the customer-profile service: designing the new data structure, opening write access for approved updates, and checking against the FlexCube core system to validate and enrich the information.
HILO e-invoice partner integration
Designed a decoupled sync: shop, staff and service-plan changes are only sent to HILO after the transaction has been saved, and every send is logged as success or failure. Moved 9 functions to HILO's new interface, added VAT calculation and invoice-info checks, and left room to add new partners without touching the core.
IBFT/NAPAS reconciliation reports
Built 8 Excel report exports (debit notices, credit notices, copy, inquiry, return, dispute, reconciliation, single inquiry) drawing on the bank's data store. Every report follows the same pipeline: validate the request → fetch data in pages of 2,000 records, up to 100,000 → export the file → write an audit log. Files are password-protected and watermarked before they reach the user.