#92
B
Rank #187
Cal.com
Open-source scheduling platform positioned as a Calendly alternative, built on Next.js. Like many Next.js apps, NEXTAUTH_URL and NEXT_PUBLIC_WEBAPP_URL get compiled into the client bundle at build time.
61.8
/ 100
⚙ Full Stack
Next.js full-stack app (API routes + React), Postgres via Prisma ORM, optional Redis for rate limiting, background workers for calendar sync jobs.
📈 Scaling Analysis
Next.js API routes scale horizontally well when stateless, but the compile-time URL baking means any domain change forces a full rebuild — a recurring self-host friction point that shows up across most Next.js apps in this batch.
🚀 Running on Nexlayer
App pod plus postgres pod; NEXT_PUBLIC_WEBAPP_URL must be set to the final Nexlayer domain *before* build since it's baked into the client bundle, not read at runtime. mirror.gcr.io/library/node covers the build image; calendar OAuth callback URLs also need to match the deployed domain exactly.