My second brain now runs on two machines

I close my MacBook every evening. For weeks, that was the design flaw in my setup.

Everything I know sits in Obsidian as plain text files: projects, daily log, training data, every job analysis. 1384 files as of today. At seven in the morning three programs go to work on them. They score new job postings, pull my training data and check whether yesterday's log exists. Reliable, with one exception: laptop closed, nothing happens.

The fix is a Mac mini that simply keeps running. Except it is useless as long as it does not have the same context as my laptop.

Obsidian ships its own sync: five euros a month I would rather not spend. iCloud causes trouble with versioning. GitHub means pushing by hand all the time. So I looked for a detour.

Why I do not ask every five minutes

The naive solution is polling: a small program asks every five minutes. Anything new? And again: anything new? The machine works the whole time, mostly to find out that nothing has changed.

Syncthing runs instead. It has macOS notify it the moment something happens in the folder. I save a file and it goes out right away: straight across the home network, encrypted, no cloud in between.

The text I am typing here sits on the other machine about eleven seconds later.

The versioning I would have missed with iCloud comes for free. The mini keeps thirty days of old versions of every file. If I delete something on the laptop by accident, I pull it back out there.

One thing I had to learn: Obsidian writes its window layout into a file in the middle of the vault. It changes on both machines constantly. Sync it and you build yourself daily conflicts over nothing. It is on the ignore list now, together with the .DS_Store files macOS leaves everywhere.

And so the mini does not doze off after all: sleep disabled while it is on power. A machine that is supposed to work at seven in the morning must not be asleep at seven.

Two machines, one vault

Syncing was the precondition for the move, not the move itself. That part is done too: the three programs start on the mini in the morning, and on the laptop the alarm is off. It had to be. Two machines editing the same files are not a backup. That is a conflict machine.

This is what I built the whole thing for: something works inside my vault on the mini while I sit at the MacBook writing. It ticks off tasks, creates notes, cleans up behind me. I keep writing and nobody pulls the file out from under my cursor. Not a single conflict so far.

Context is the most important thing I have learned about working with AI. A model without context gives me an answer that is right for someone. A model with my vault gives me an answer that is right for me. That is why everything I know sits there as a text file. And that is why it has to be on every machine that runs something for me.