5 years of backend experience focused on payment and transaction systems. I have owned the payment flow for four products — e-commerce, online courses, a gaming platform and a booking marketplace — and led several projects from scratch, including launching a transaction platform with payments and e-invoicing.
I integrate third-party payment providers such as NewebPay and ECPay, and know signature verification and reconciliation well. Across projects I have built high-concurrency services on sharded databases and microservices, adding message queues to absorb traffic peaks, failure retries and proactive order recovery for reliability.