Uber VO 面试真题解析：Design a Backend System for an E-commerce Browsing Experience

Design a backend system for an e-commerce website that shows a list of merchandise. The system should focus on the browsing aspect, not on how to make purchases.

Use popularity to select what to display as the top items. Build an offline batching pipeline to process what’s popular.

这道题考察的是电商浏览页的后端设计思路，重点不在下单支付，而在“哪些商品应该展示给用户”。核心可以围绕热度统计、离线批处理、排行榜生成和定时刷新来展开：先采集浏览、点击、停留等行为数据，再通过批量任务汇总商品热度，生成 Top Items 列表供前台展示。回答时要说明数据管道如何设计、如何避免实时计算压力、如何处理热门商品更新延迟，以及如何保证结果可扩展、可排序、可缓存。