TL;DR — Black Friday: 100x Traffic Spike

You run an e-commerce platform currently handling 10K requests per second on a monolithic architecture. The stack is a single Node.js monolith behind an Nginx load balancer, one PostgreSQL primary database, and a Redis cache layer. The system serves product pages, handles cart operations, and processes orders through a synchronous checkout flow. Key features: Product catalog browsing must remain fast under peak load. Cart operations must not lose items during traffic spikes.