Scribe
Zero-Leak On-Device Audio & Video Transcription Studio
Designed and deployed a privacy-first video and audio transcription PWA that transcribes recorded briefings, client strategy calls, and voice notes locally with zero cloud API token costs.
The Engineering Case Study
The Problem
Agencies dealing with proprietary client strategy or confidential recordings cannot ethically or legally upload audio files to public AI transcription SaaS tools like Otter.ai or Descript due to confidentiality breaches, NDA compliance, and ballooning per-minute subscription charges.
How It Was Engineered
Scribe processes audio locally within the browser sandbox using modern speech recognition interfaces and offline audio buffers. Transcripts are segmented with timestamps, formatted into conversational blocks, and securely stored in local browser IndexedDB storage. Users can export structured meeting notes, timestamped subtitles (SRT), or raw Markdown with a single click.
Engineering Hurdles Solved
Managing memory pressure during long-form recordings (60+ minutes) on memory-constrained mobile devices. Cynthia implemented streaming audio chunking that flushes intermediate PCM buffers while persisting transcription deltas incrementally to IndexedDB, preventing browser tab crashes.
Business & Production Outcome
Guarantees strict compliance for client non-disclosure agreements while saving the agency thousands in recurring SaaS transcription fees. Speeds up discovery synthesis by generating structured meeting notes in real time.