Fast Notes

I write in an Obsidian vault on my laptop, and getting a thought into it from my phone was always the slow bit. So I sat through a product interview with an agent, answered every question about how I actually capture things, and turned the answers into a brief.

The brief is short. Open the app and the keyboard is up. Save to the phone before anything else happens. Write each note as a Markdown file into the folders I already have, so Obsidian and Reflect keep working. Start voice from the Lock Screen, a widget or the app icon, and don’t make me press Save.

It’s a native Swift app because speed was the whole point. Text saves atomically on the phone, and empty drafts never become files. Voice records through the lock with a Live Activity Stop button, transcribes on the phone and keeps the audio until the text is safe. If there’s already text in the note, dictation appends to it with a small marker instead of starting a new note.

Sync goes through Google Drive, and an upload only counts as done once the file reads back byte for byte. The first real test note turned up in both Obsidian and Reflect on my Mac.

These screenshots are from the simulator test runs, with made-up notes. My real notes stay out of them.

Once capture worked, I wanted to ask questions of what I’d written. Open a note and choose “Ask this note”, hold a folder for “Ask this folder”, or ask the whole vault. It runs through the ChatGPT plan I already pay for, with no paid API behind it, and it can read notes but has no way to change them. Conversations save on the phone and get short names in the background.

Then the folder list started to stall. Rather than guess, I ran Time Profiler against the installed app on my phone. Almost every sample in a 15-second trace was the folder suggestions doing slow string matching on the main thread, every time the screen refreshed.

The fix moved browsing, search and date grouping into background work, reused results that hadn’t changed and rewrote the matcher to prepare folder names once. On a test vault of 5,000 notes the matcher went from about 23 ms to 0.6 ms. That’s the matcher, not the whole app.

Since then it has picked up smarter folder suggestions, a guard that stops dictated filler words becoming hashtags, 25 rotating pencil app icons and a Recents view across every folder. It’s installed on my phone. A few acceptance checks are still open, including offline transcription and my work laptop.