YouTube: what you will build

The largest of the three: a video platform backend. Accounts and channels, an upload that survives a large file, playlists, subscriptions, and a home feed.

By the end you will have:

• Sign-up with a password or Google, and a channel per account
• An upload that stores the file and hands it to a background job, with a video that is honestly not yet watchable until that job finishes
• Visibility — public, unlisted, private — enforced on every read path
• Playlists, ordered, reusing the positions from Trello
• Subscriptions, and a feed that is one query no matter how many channels someone follows

The hard parts

A video has states, and pretending otherwise breaks the player. Between “the upload finished” and “this can be watched” there is real work — and if the API returns ready the moment bytes land, every client shows a broken video. The status column is the first thing on the schema for a reason.

The feed must not be a query per channel. Someone following 200 channels should cost one query, not 200. Chapter 6 builds it and shows the output.

Visibility is checked on every path, not just one. A private video is reachable through the channel page, the playlist it sits in, the feed, and its own URL. Four places, one rule — so the rule lives in one function.

The shape

src/
  schema.ts               channels, videos, playlists, playlist_items, subscriptions
  visibility.ts           the one rule, used by four routes
  jobs.ts                 the processing job
  routes/
    channels/…            create, read, subscribe
    videos/…              upload, watch, update
    playlists/…           create, add, reorder
    feed.get.ts           the subscription feed

Before you start

bun create theoven tube --db sqlite --auth basic
cd tube && bun install
bun add @theoven/storage @theoven/queue

Channels and accounts →