Visa's system design, explained end to end

Visa's complete system design, walked end to end with the real numbers and the real diagrams. The four parties (you, the shop, the shop's bank, your bank); why the answer and the money are split (authorization now, clearing and settlement later); the clocks in Visa's own rules and Stand-In Processing when a bank is silent; paying online with 3-D Secure; netting and settlement; paying abroad and who converts the currency; tokens; a chargeback, step by step; the 2018 Visa Europe outage; and today's four data centers. Sources: Visa Inc. Form 10-K (fiscal 2025 and 2018), Visa Core Rules (April 2026), Visa Europe's letter to the UK Treasury Committee (June 2018), Visa press releases and fact sheets. The full interactive system design, every piece clickable, is free at dataforall.dev Not affiliated with or endorsed by Visa. The Visa logo is used only to identify the company discussed. #systemdesign #softwareengineering #visa #payments #dataforall 0:00 Intro 1:11 What happens when you tap 2:20 Paying online: your bank checks it is you 4:03 Pay with a phone wallet: the card number never travels 5:01 1 June 2018: two data centers, one bad switch