# Serverless (/academy/serverless)



You do not rent the whole kitchen for a weekend demo.

**Serverless** means you ship a function — one job — and a host runs it when someone asks. A request arrives. A [runtime](/academy/runtime) wakes. Your code runs. It goes quiet. The bill is for the minutes it was awake, not for a box that hummed all night with nobody in the room.

There is still a [server](/academy/server). The useful part is you do not name the box, patch it on Saturday, or guess how big it should be before the hallway fills up.

Vercel, Cloudflare, Convex — this is the default lobby after you [deploy](/academy/deploy) a create-hackhaton-space-stack app. You did not SSH into anything. You pushed, and a pool of machines borrowed a slice of themselves for your route.

**The yawn**

If nobody has hit that function in a while, the first request waits while the kitchen lights flicker on. That is a cold start. Fine for a [webhook](/academy/webhook) that fires when Polar says "paid." Awkward for a voice [agent](/academy/agent) that cannot eat a one-second pause. [Workers](/academy/worker) and [edge](/academy/edge) are dialects of the same rental: smaller rooms, closer to the door, still not a box you pet.

Always-on is a different product. A long [process](/academy/process), a fat [database](/academy/database) driver, a socket that must stay open — those want a room that does not vanish between guests. Serverless wants a guest, a dish, a check.

Spikes are why people pick it at a hackathon. Forty judges refresh at once. The host runs forty copies and throws them away. You did not upgrade a plan during the pitch. The [CLI](/academy/cli) already pointed you at that lobby when you picked a host that deploys functions instead of a box.

**What this unlocks**

Once you see the rental, "we need a server" stops meaning "we need a box we babysit." It means "we need something that runs when asked." Pay for the dish. Leave the building to the landlord.

A weekend app that sleeps between clicks should not pay rent on an empty room.