Obsidian
$ obsidian --vault ~/brainThe anti-SaaS second brain
Obsidian is a folder of plain-text markdown files on your disk. That is the entire architecture — no account, no cloud database, no web app pretending to be a desktop app.
The constraint is the feature. Notion tries to be your database, your wiki and your project manager, and gets slower with each one. Obsidian stays local and stays fast, because a note is just text.
Why it holds up for deep work
Deep work dies by interruption, and most note apps are interruption machines: a sync spinner, a nudge, a 'someone commented' badge. Obsidian is offline-first. Nothing phones home while you think.
Plain text means zero render lag, so capture is instant — pair it with a launcher like Raycast and a thought goes from impulse to note without breaking focus. One vault, one window, no tab sprawl. The tool gets out of the way — the only job a deep-work tool actually has.
Links over folders
Folders make you decide where a thought belongs before you understand it. You rarely can, so things get lost.
Bi-directional links let you connect notes instead of filing them — the way recall actually works. Link as you write; the structure emerges later. The graph view is the party trick. The backlink is the engine.
Built for developers
If you write code, this is the only note app that respects you. It treats your knowledge the way you treat a codebase: plain text you control.
Your data, in plain text
The vault is markdown on your filesystem — greppable, diffable, versioned with git. There is no export button because there is nothing to export from: you already own every byte. No lock-in, ever.
Scriptable and future-proof
If you can script a text file, you can automate your notes — generate, parse, transform. And plain markdown will still open in fifty years, long after this decade's SaaS darling sunsets its servers.
The trade-offs
No tool earns a 10 without honest costs. Obsidian's are real.
Paid sync
The app is free for personal use, with no limits. Cross-device sync is the paid part: official Obsidian Sync runs $4 per month billed annually. You can route around it with git or iCloud — but that is setup you own.
The plugin rabbit hole
The community-plugin ecosystem is vast, and that is the trap. Pile on enough plugins, themes and conventions and your second brain accumulates the same constraint decay that kills teams — every addition taxes every future note. Install deliberately, or the tool becomes the distraction it was built to kill.
The verdict
One vault. Plain markdown. The smallest set of plugins that does the job. Set it up like that and Obsidian is the closest thing to a second brain a developer can actually own.
Strip the noise. Ship the work.