Flash Sale Scaling

Overview

Flash sales and product drops generate traffic spikes 50–100× normal load, arriving within seconds of sale start. Without preparation, the checkout service collapses, inventory oversells, and customers see error pages. This skill covers the infrastructure patterns needed to handle extreme traffic: pre-warming, queue-based order intake with back-pressure, Redis-based atomic inventory reservation, and circuit breakers that degrade gracefully under load.

When to Use This Skill

• When planning a flash sale, limited product drop, or major promotional event
• When past sales have caused checkout timeouts, oversells, or database failures
• When Black Friday/Cyber Monday planning is underway and infrastructure needs review
• When a new product announcement is expected to drive sudden high-demand traffic

Core Instructions

Step 1: Determine your platform and what you can control