Vercel is a cloud platform for deploying web apps and the company behind Next.js. Its own site and dashboard run on Next.js and Turborepo, while the platform underneath mixes AWS Lambda, a Rust core, Go at the edge and a Kafka and ClickHouse data pipeline.
Error tracking in the dashboard through @sentry/nextjs.
How they built it
Dogfooding Next.js on vercel.com
vercel.com started as one large Next.js app serving both marketing pages and the logged-in dashboard. As it grew, build times climbed and small changes triggered full builds.
The team split it into vertical microfrontends with Next.js Multi-Zones inside a Turborepo monorepo, using feature flags to move traffic over gradually. The result was over 40% faster preview builds and local compilation.
In 2022 the team took the dashboard's Lighthouse score from 51 to 94. Most of the wins were about shipping less JavaScript: importing only the needed parts of Sentry, lazy-loading Stripe and Google Tag Manager scripts, and caching functions that ran hundreds of times per render.
They also leaned on Next.js features such as next/image and inlined font CSS.
Turborepo was first written in Go, which fit the project early on. As the codebase grew and merged with Turbopack, which is written in Rust, Go started to underserve it.
The team ported it incrementally, running Rust and Go side by side for a while, and finished the migration with Turborepo 1.11.
Vercel Functions run on AWS Lambda, which at first could not stream responses. To add streaming, Vercel built a secure TCP-based protocol from Lambda back to its own infrastructure, with a Rust core as the glue.
That work became Fluid compute, which reuses running instances across requests to cut cold starts and costs for I/O-heavy workloads such as AI apps.