At Nari Information, I replaced Mazzucchi’s phone-and-paper ordering process with customer and admin apps that processed 2,000+ orders. I also built a price-finalization flow that validates item IDs and updates an order in one SQL statement, preventing partial charges.
I run Kotlin/Ktor and PostgreSQL backends for products including LevelUp Piano and Coedu · Bit Kingdom. For Coedu, I implemented PayPal and KG Inicis payments with provider-verified settlements, signed webhooks, refunds, and recurring billing; I also maintain internal operations tools and an ERP at MHP Co., Ltd.
