Case Study: Cash App scales to 400TiB and 4 million QPS on PlanetScale
Key results
The challenge
Cash App, the mobile payments app from Block, ran its databases on a self-hosted Vitess setup that required maintaining a forked version of Vitess and constant, time-consuming software upgrades. Because Vitess was deployed on top of existing MySQL infrastructure rather than in Kubernetes, operations were manual and error-prone. As data demands grew, the overhead of scaling in its in-house data centers became difficult to sustain.
The solution
Cash App migrated from its self-hosted Vitess to PlanetScale's managed platform, citing PlanetScale's deep Vitess and AWS expertise and its ability to meet strict regulatory requirements. The move offloaded cluster management and let the team scale without time-consuming hardware upgrades.
“The actual cutover was almost comically boring, which is exactly where I wanted to be after all the upfront work we put in.”
AYAaron YoungEngineering Manager, Cash App
The results, in context
At peak times, Cash App's database handles approximately 3–4 million queries per second across 400 shards, totaling around 400TiB of data. By moving to PlanetScale Metal, Block saved 64% and cut p99 latency by 50%, while gaining more stable performance with fewer spikes during peak loads and Vitess-specific dashboard insights for its engineers.