How Dub grew to 3,000 active domains with Vercel’s multi-tenant SaaS toolkit

Scale, without the domain grind

Dub, an open-source link management platform for marketing teams, routes traffic across a growing number of custom domains. The platform now handles over 3,000 active domains—growing 25% month-over-month—and processes 5 million link redirects per month, a figure increasing at a 40% monthly rate. According to CEO Steven Tey, the key to that growth has been offloading the hardest parts of domain infrastructure to Vercel.

The API-first approach to custom domains

Dub relies on the Vercel Domains API to provision custom domains on behalf of its users. What is typically a convoluted backend problem—setting up reverse proxies and issuing SSL certificates—is reduced to a single API call. Vercel handles the certificate issuance and proxy configuration, while Dub provides users with clear DNS setup instructions.

“We needed a solution that was straightforward, and Vercel delivered just that with their API. An otherwise painful process, Vercel allows us to efficiently add or update domains on our platform and provides clear instructions for our users to configure the appropriate DNS records for those domains.”

Steven Tey, CEO at Dub

SSL without the usual overhead

SSL certificate management is notoriously costly and complex, particularly when spanning multiple providers. Dub has used Vercel from the start to sidestep that burden. By leveraging the Domains API, Dub avoids the expense and maintenance overhead of certificate management while maintaining high security standards. For end users, that translates into faster custom domain activation and fewer setup hurdles, which Dub credits with improving retention and satisfaction.

Managed infrastructure for redirect volume

Dub's infrastructure needs extend beyond domain provisioning. The platform must reliably serve and track millions of link redirects each month, with traffic expected to climb significantly by year-end. Vercel's serverless compute handles that increasing volume without requiring Dub to manage scaling logic or capacity planning. The setup lets Dub focus on product iteration rather than backend operations, allowing the platform to absorb traffic spikes and domain growth with minimal engineering overhead.

The result is an architecture where adding a customer's custom domain is a routine API operation, not an engineering project—making fast growth operationally feasible rather than a bottleneck.