# How Klaviyo shipped 356 internal apps in two weeks on Vercel By Steven Van ยท 2026-09-24 512 of Klaviyo's 2,000+ employees built the apps through a citizen developer program with SSO-gated, database-backed deployments by default. 512 of Klaviyo's more than 2,000 employees deployed 356 apps in the first two weeks of a new internal citizen developer program built on [Vercel](), according to a [case study]() from Vercel. Of those apps, 196 were full-stack, with their own databases, and came from teams outside engineering, including legal, marketing and HR. Vercel says builders go from idea to a live app in three minutes. Klaviyo built the program around guardrails rather than restrictions: - Every app ships SSO-gated and private by default, with builders managed through Klaviyo's identity provider via Vercel's Enterprise Managed Users and Vercel Passport. - App-to-database connections run over Secure Compute, a private network path into Klaviyo's own infrastructure, so traffic never crosses the public internet. [![]()]() ![Vercel]() Vercel The platform for frontend developers โ€” deploy, preview, and scale web apps and AI agents with zero config. [View Vercel โ†’]() [Read the original announcement โ†’]() [Read How Klaviyo shipped 356 internal apps in two weeks on Vercel on Creators Toolbox]() --- Canonical source: https://creatorstoolbox.com/blog/vercel-how-klaviyo-shipped-356-internal-apps-in-two-weeks-on-vercel