Forty files. Four manifests. One checksum each

Mamba Smith is the founder of Queen City Garage, which produces The Grand National Show: a weekly NASCAR panel show on Grand National Today where broadcasters and drivers argue about the last race and pick the winner of the next one.

When we send a panelist their clips from The Grand National Show, they do not get a ZIP. They get a link to a manifest: a locked list of exactly which files are in their package and which version each one is. Every file on that list has a checksum, a size, a version and a record of who was sent it and when.

We built that after Episode 1, when the four of us got ZIPs.

The rebuild

Episode 1 went out with 40 participant-facing files: 12 horizontal videos, 12 vertical, 12 covers and four posting-copy files, one folder per person. They were good files. They were also loose. If a file was wrong, there was no way to tell which version anyone had. If a file was right, there was no way to prove it later.

So we registered all 40 individually. Each got a hash and a size. Each was assigned to one of four versioned ten-file manifests, one per recipient. The original ZIPs were kept as immutable legacy objects, because a package that has already been sent is a historical fact and you do not edit history.

Then we built the layer around it: each recipient tied to their own manifest, an audit entry on every change, add and remove operations that create a new version rather than touching a locked one, links that open one specific version of one specific list rather than a folder, and the send and download steps that hand a recipient their link and record what they took.

The delivery workflow landed as one commit: 27 files covering the application, tests, generated types, database configuration, five server functions and nine migrations. Verification before it went live: 375 tests across 35 files passed, the production build passed, and all five server functions passed their type checks. The database test ran inside a transaction that was undone at the end, so the full path from manifest to download was proven without leaving a single test row behind.

What a recipient sees

A page. Their name at the top. Their clips first, because that is what they came for, with the covers and the posting copy below. A version number. A download that records itself.

If we reissue a package, they get a new link and the old one is revoked. The old version still exists in the record. It is just no longer live.

On our side, a person record shows the episode, the related article, every package version, the exact files in each, every send and every download. That is the chain of custody we did not have on Episode 1.

The finding worth keeping

The postmortem's conclusion was not "edit better." The editing was not the problem. The conclusion was that the failure was chain of custody: there was no single episode-owned path from source through master, clips, package, recipient, send and download. Each piece was well made and none of them knew about the others.

That is why Episode 2 began with the episode record and not with folders, and why the eight gates treat the package lock as a gate rather than a courtesy.

What the machine does here

Hashing 40 files is not interesting work for a person and it is exactly the work a person skips at one in the morning. The machine hashes every file, checks every hash on registration, builds the manifest, renders the recipient page, and refuses to lock a package that contains a file it has not registered.

A person decides what goes in the package and who it goes to. The machine makes sure that what was decided is what was sent, and that we can prove it in a month.

What a person did: chose the clips, chose the recipients, wrote the posting copy in each panelist's voice. What the machine did: registered, hashed, versioned and locked every file, and recorded every send and every download.

This is No. 03 in How We Make the Show, the Queen City Garage build log on producing The Grand National Show. Watch the show at Grand National Today.