Payment Integrations in Two Days with Claude Code
How I cut payment-provider integrations from a week to 1–2 days with Claude Code: goals first, high-risk logic first, review by a fresh agent.
#payments · 8 posts
How to Integrate a Payment Provider That Has No Sandbox
No sandbox and docs that don't match production? Simulate from the docs, send one tiny real payment, log every call, and fix the gaps before customers see them.
Why Sending $1 Cost Me $15, and the Workarounds I See Back Home
A $1 wire cost me $15; $78 in USDT cost under $3. Fees belong to the rail, not the amount, and Vietnam's payment workarounds show what fintech could build.
In Japan, You Can Buy Something Online and Pay for It in Cash at 7-Eleven
Konbini payment lets Japanese shoppers check out online and pay in cash at a convenience store. Why it works, and what it means for payment system design.
Designing a Payout System: What Payment-In Tutorials Don't Tell You
Payouts fail in ways payment-in doesn't. Lessons on beneficiary verification, double sends, compliance-first routing, and reconciliation.
How Do We Know a Customer Has Actually Received Their Money?
Webhooks vs. polling: how a payment system actually confirms money has arrived, explained through a grocery-store QR code.
Notes on Evaluating a New Payment API Before You Build the Adapter
Test the field mapping before frontend builds on top of it — a checklist for what to verify before writing adapter docs.
Design patterns aren't a catalog — they're a way to predict where change will hurt
A payment infrastructure engineer's notes on applying Chain of Responsibility, Adapter, Strategy, and Observer to a real virtual account creation flow.