Notes on Prateek Sharma

Whisper's turbo model beat large on noisy audio, in practice

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

Building the Video Translator , the assumption going in was that OpenAI Whisper’s larger model would transcribe more accurately. In practice, on clips with loud background music, the turbo model did noticeably better than large — it seems to tolerate messy audio better rather than just being a faster, lower-quality option. Separating vocals from background music first (with demucs) didn’t help as much as expected either; Whisper handled the mixed track better on its own. Worth trying turbo first rather than assuming bigger is more accurate.

Composite index column order should match the query, not the schema

Sun, 30 Aug 2026 00:00:00 +0000

In the TTS Study Assistant notes table, queries filter by user_id always and domain often, so the index is declared in that order:

CREATE INDEX idx_uid_did ON notes(user_id, domain);

A composite index is only fully useful as a left-prefix: this index serves WHERE user_id = ? and WHERE user_id = ? AND domain = ?, but not WHERE domain = ? alone. The rule of thumb is to order columns by how the queries actually filter — most selective / most-always-present first — not by declaration order in the table, and not alphabetically.

Daemon threads for WebSocket keepalives

Sat, 29 Aug 2026 00:00:00 +0000

A WebSocket connection that needs periodic pings to stay open shouldn’t run that ping loop on a plain, non-daemon thread. In the WazirX Java connector , the ping thread is started onOpen and marked setDaemon(true) before starting it:

pingThread = new Thread(new PingMessage(this));
pingThread.setDaemon(true);
pingThread.start();

A non-daemon thread keeps the JVM alive until it finishes. If a caller opens a socket, forgets to close it, and the rest of the application shuts down, a non-daemon ping thread will keep the process running indefinitely. A daemon thread just gets killed when everything else is done — which is the right default for background keepalive work that isn’t itself the point of the program.