Corey Losenegger

Roadblock Title:

Black Friday Took Down Our Checkout: How We Isolated the Financial Core

Time:

Wednesday - 1:00 PM (Windows)

Abstract:

When you’re processing billions of dollars in consumer loans, uptime isn’t aspirational; it’s a contractual and regulatory obligation. But we’re also running a consumer mobile app with millions of users, marketing campaigns that drive unpredictable traffic spikes, and a browser extension that lives on every shopping site on the internet.

On Black Friday 2024, we learned the hard way that these two worlds were dangerously coupled: app traffic overloaded shared database resources and took down our checkout flow, the one thing that absolutely cannot go down.

This talk covers how we built a multi-layered isolation strategy (sub-minute kill switches, per-feature throttling, graceful degradation UX, API migrations to decouple read paths) that lets us aggressively grow our consumer-facing surfaces while placing a hard boundary around the correctness and availability of the core financial transaction path. The goal isn’t to slow down the app team or the marketing org. It’s to give them room to push the envelope without ever risking a customer’s ability to check out or make a payment.

Bio:

Corey is a builder who’s been making products on the web for over 20 years. He is a member of Affirm’s Architecture Team where he serves as the technical lead for Affirm’s Consumer organization. His team owns the company’s debit card, savings account, marketplace, and other consumer-facing products. When he’s not building software or chasing his two small boys around Denver, he produces electronic dance music.