Under the hood: Shipping #friendsday videos

What this post added

This post details the engineering challenges and solutions for generating and shipping hundreds of millions of personalized #friendsday videos. Key contributions include: load testing and optimization of the video generation pipeline (achieving a 69% reduction in processing time via multithreading), capacity planning considering CPU, memory, storage IOPS, network bandwidth, and power availability, implementing an automated system for safe infrastructure utilization by dynamically allocating machines and blocklisting problematic ones, developing a ranking system for photo selection using signals like break-up checkup, blocks, and user interactions, and leveraging AI image understanding to assess photo quality and relevance. It also describes a staggered rollout plan to manage CDN load across different continents and time zones, and highlights the rapid development of Android and iOS UIs using React Native.