Campaigns

Prerequisite: Familiarity with the concepts introduced in Part 4 — Sre Chaos Engineering. Review it first if the terminology in this part is unfamiliar. Answer-first: Scaling for billion-yen cashback campaigns requires pre-warmed Redis cluster caching, token-bucket rate limiting at the API gateway, and async queue-based payment processing to shave peak traffic spikes. Answer-first: The PayPay campaign architecture isolates high-throughput reward campaigns from core payment processing. By evaluating campaign eligibility out-of-band and writing reward points asynchronously using event queues, PayPay prevents promotional traffic spikes from impacting critical credit card processing pipelines. ...