Redux over Context
Three roles write to the same classroom state at once. Under Context every transcribed sentence re-rendered the whole tree.
BC
2018 to 2023 · startup · Founder & Software Engineer
Aurem
Online class excludes whoever cannot hear. Live captioning with the Web Speech API, a collaborative whiteboard in Fabric.js, and an Electron client whose transparent overlay captions on top of any software.
the company on LinkedIn also in the timeline
The problem
Hybrid and remote classes assume everyone can hear. Someone with hearing loss depends on an interpreter in the room or on the captions the video player generates, and those are gone the moment the teacher presents from PowerPoint, from a PDF, or from anything outside the browser.
What I built
An ecosystem on three fronts: an LMS for institutions, a virtual classroom with live captioning, and a desktop client that captions on top of any application.
Technical decisions
Fabric.js on the whiteboard
Annotation had to travel as vector. As an image it did not fit the socket and went blurry on zoom.
WebSockets over polling
A caption that lags is useless. The budget ran from speech to text on screen, and polling spent it on the round-trip alone.
Electron frameless with click-through
The caption sits on top of PowerPoint without stealing the presenter click.
Web Speech API
Transcribing on the client cut one server round-trip per sentence and kept audio off the wire.
Result
It served more than a thousand students and won the Santander Award. The company closed in 2023, but the product ran five years in production while I worked on other teams.