ITPUB

Feb 22, 2026 · Backend Development

Designing a Cost‑Controlled “Cut‑One‑Knife” Promotion Engine for Massive Concurrency

This article breaks down the algorithm and architecture behind Pinduoduo's "cut‑one‑knife" promotion, explaining how dynamic pricing based on user value, Zeno’s paradox, Redis atomic operations, and anti‑fraud measures ensure users receive phones without the platform incurring losses even under massive traffic and bot attacks.