Full-Stack Engineer: YouTube Transcript Highlighter

I am looking for an experienced developer to build a core feature for a web application that allows users to interact with YouTube transcripts in a highly specific way.

The goal is to create an experience similar to the "Light Cone" podcast app (see attached screenshots), where text and video are perfectly synced.

This is the first of several projects in my pipeline.

I am looking for a talented, long-term technical partner to grow with as I expand into specialized tools and marketplaces.

The Core Workflow

Import & Sync:

Using the YouTube Data API and IFrame Player API, the app must pull a video and its transcript.

Interactive Highlighting:

Users should be able to highlight specific text segments in the transcript. As the video plays, the corresponding text must highlight in real-time.

Selective Playback:

I need the ability to "Play Highlights Only." The player should automatically skip any parts of the video that aren't part of a saved highlight.

Folder Organization:

Users must be able to save these highlights into custom folders (e.g., "Startup Advice," "Neuroscience") and play back all highlights within a folder as a continuous "reel.", mix, etc.

Technical Requirements

YouTube API Mastery:

Deep experience with the YouTube IFrame Player API (specifically controlling playback via seekTo and monitoring state with onStateChange).

Transcript Logic:

Proficiency in mapping JSON/XML transcript timestamps to the video player's current time.

Frontend State:

Ability to manage complex highlighting states (we need to save the exact start and end timestamps for every "clipped" sentence).

Storage/Backend:

Experience with a database (Firebase, Supabase, or PostgreSQL) to store highlight objects and folder structures.

Deliverables

API configuration for YouTube Data & IFrame Player.

A synced transcript component where clicking a word jumps the video to that moment.

Logic that "loops" or "sequences" multiple timestamped segments from different videos within a folder.

A clean, responsive UI for the transcript/video split view.

Future Opportunities

I am looking for a developer who is interested in more than just a one-off task.

If we work well together, I have additional projects in the pipeline, including:

Personal Development & Neuroscience Tools:

Apps focused on cognitive tracking and spiritual growth.

Specialized Marketplaces:

A custom platform for high-end vehicle conversions (van-flipping business model).

Advanced AI Workflows:

Expanding our transcript tool into a larger research ecosystem.

To Apply, Please Answer:

Have you worked with the YouTube IFrame API to control playback based on external text triggers before?

How would you handle the "Play Highlights Only" logic to ensure smooth transitions between non-consecutive timestamps?

What is your preferred tech stack for a project that requires real-time data syncing?

Are you available for ongoing work on a variety of different projects if this first phase is successful?

Contract duration of 1 to 3 months.

Mandatory skills:

youtube api, Supabase, Java, JavaScript, React, Web Application, TypeScript, , API Integration, AI App Development