Blog on Avi Chandra

Editing the same file on two computers

Mon, 31 Aug 2026 00:00:00 +0000

Here’s a problem that sounds simple until you actually sit down and try to solve it.

You’re building a local-first app. Let’s call it Thangs, a Things 3 clone for people who like their to-do lists fast, offline, and free of subscription fatigue. The whole pitch is that your data lives in a file on your machine, and if you want sync, you just drop that file in Dropbox or iCloud and let the cloud do its dumb cloud thing.

Arrhenotoky and AI swarms

Mon, 24 Aug 2026 00:00:00 +0000

There’s a word I want you to sit with for a second: arrhenotoky. It sounds like a neighborhood in Athens where you’d get a very good lamb dish. It is actually one of the strangest reproductive systems on Earth, and I’ve become convinced it says something about where AI systems might be headed. Not human-shaped. Hive-shaped.

Bear with me. The biology comes first, and the biology is the good part.

A sync engine is mostly conflict policy

Thu, 30 Jul 2026 00:00:00 +0000

Every time I start a sync engine I spend the first week on transport, and every time that turns out to be the week that did not matter.

Transport is solved

Batching, retries, resumable cursors, a version vector so you know where you left off:

type Cursor = { replica: string; clock: number }

async function pull(since: Cursor): Promise<Op[]> {
 // page until the server says it has nothing newer
}

There are a dozen good write-ups on all of it, and the code ends up looking the same regardless of who wrote it.

Shipping to one campus at a time

Thu, 18 Jun 2026 00:00:00 +0000

mrmr launched at one university before it launched at two. That was not a growth strategy, it was the only thing that worked.

The same software, three different products

An anonymous feed changes character entirely with size, and nothing in the code changes with it:

~100 people. It is a group chat.
~1,000 people. It is a newspaper.
10,000 strangers. It is a sewer.

Only the boundary moved.

Scope does the work a filter cannot

Restricting the feed to a single campus handles moderation in a way no classifier has managed for me. Everyone posting is someone you could plausibly stand next to in a queue tomorrow, and that fact alone removes most of what makes anonymity grim.

Frame buffers beat photos

Sat, 02 May 2026 00:00:00 +0000

The first version of the Lorcana scanner had a shutter button. You lined up a card, tapped, waited, got a result. About three seconds a card, and your thumb hurt after a playset.

The second version never captures a photo at all.

Read the buffer, skip the capture

Recognition runs on whatever is already flowing through the capture pipeline:

func captureOutput(_ output: AVCaptureOutput,
 didOutput sampleBuffer: CMSampleBuffer,
 from connection: AVCaptureConnection) {
 guard let pixels = CMSampleBufferGetImageBuffer(sampleBuffer) else { return }
 recognizer.submit(pixels) // no still capture, no pipeline flush
}

The whole speed win comes from deleting the capture step: