Capacity planning: 2 real scaling case studies
2 of the 94 engineering write-ups in our database are tagged with the technique "capacity planning". They come from 2 companies (Meta and Shopify) and were published between 2020 and 2026. Often combined with load testing (2). 1 of the 2 state concrete scale numbers, for example "30 million+ WhatsApp messages/sec" (Meta). Each card below links to our short summary and the original post.
The standout example: pre-provisioned capacity buffers carried WhatsApp past 30 million messages per second during the 2026 World Cup final.
2026 World Cup: Breaking Records, Spiky Charts and Reliability at Scale
How Meta absorbed the 2026 World Cup, when WhatsApp set a record of more than 30 million messages per second during the final. Pre-provisioned capacity buffers were the most effective lever, alongside country-level shedding of non-critical load, load-testing and resizing 100+ services, forecasting each region's peak separately, and no deploy freeze.
Capacity Planning at Scale
How Shopify plans and checks capacity for traffic peaks like BFCM using forecasts and scalability tests.