JobInsight

A Chrome extension that reads the LinkedIn job posting you're looking at and answers the questions a job seeker actually screens on — does it sponsor, does it require citizenship, how many years of experience — in a draggable overlay, without leaving the page.

JobInsight is a browser extension, not a hosted site, so there is no live demo link — it runs inside LinkedIn. Load it in about a minute and it works on any LinkedIn job listing.

Screenshots

Two more shots would round this out. Drop each file at the path shown and uncomment the matching line.

Screenshot	Path	Why it matters
The overlay close-up on a single job, with the sponsorship and citizenship rows visible	screenshots/overlay-detail.png	The product in one frame — the fields people install this for
The popup showing the Google sign-in state	screenshots/popup-signin.png	Shows the auth gate that sits in front of the backend proxy

What it shows

For each job posting, the overlay extracts:

• Experience — years required
• Education — degree level, and whether required or preferred
• Sponsorship — Sponsors / Does Not Sponsor / Not Mentioned
• US Citizenship — flags if citizenship or security clearance is required
• Summary — a 2–3 sentence overview of the role
• Keywords — job-specific technical terms, highlighted in the job description

What it demonstrates technically

• The API key never ships to the client. The extension holds no OpenAI credential; it posts job text to a Node/Express proxy that holds the key server-side. The proxy gates /api/analyze on the configured extension origin, and CI tests that gate specifically — it is the security boundary the whole design rests on.
• A complete Chrome MV3 architecture: a content script that scrapes and renders the overlay into LinkedIn's DOM, a service worker that brokers the backend calls, and a popup that owns Google OAuth via chrome.identity.
• A 7-day client-side cache (JOB_CACHE_TTL in content/linkedin-scraper.js) keyed per job, so revisiting a posting is instant and costs nothing — the cheapest possible fix for redundant LLM calls.
• Structured extraction, not free text. GPT-4o-mini is prompted to return six fixed fields the UI can render directly, rather than prose the extension would have to parse.
• CI catches the failure mode that is invisible until reinstall — it validates manifest.json, checks every script the manifest names actually exists, syntax-checks every extension script, and audits production dependencies.

Stack

Layer	Technology
Extension	Chrome MV3, vanilla JavaScript (content script, service worker, popup)
Backend proxy	Node.js, Express 4
Auth	Google OAuth 2.0 via chrome.identity
AI	OpenAI GPT-4o-mini
Hosting	Render (backend proxy)
CI	GitHub Actions (Node 20 and 22)

Install

The extension is not on the Chrome Web Store — load it unpacked:

1. Clone this repository.
2. Open chrome://extensions in Chrome.
3. Enable Developer mode (top-right toggle).
4. Click Load unpacked and select the repository root (the folder containing manifest.json).
5. Click the JobInsight icon in the toolbar and sign in with Google.
6. Open any LinkedIn job listing — the overlay appears in the top-right corner. Drag it to reposition, or resize it from any edge.

The packaged extension points at the deployed proxy at https://jobinsight-6nyq.onrender.com, so it works out of the box after sign-in.

Quick start (backend proxy)

Only needed if you want to run the proxy yourself. Commands are the scripts in backend/package.json.

cd backend
npm install
cp .env.example .env     # then set OPENAI_API_KEY
npm run dev              # node --watch server.js
npm test                 # node --test

The proxy exposes POST /api/analyze and GET /api/health.

Cost

Uses GPT-4o-mini. Each job analysis costs roughly $0.0003–0.0005 — less than a tenth of a cent.

Project structure

JobInsight/
├── manifest.json               # Chrome MV3 config
├── backend/                    # Express proxy that holds the OpenAI key
│   └── server.js               # POST /api/analyze, GET /api/health
├── background/
│   └── service-worker.js       # Extension -> backend API calls
├── content/
│   ├── linkedin-scraper.js     # Page scraping, overlay, 7-day cache
│   └── overlay.css             # Overlay styles
├── popup/
│   ├── popup.html              # Sign-in UI
│   └── popup.js                # Google OAuth & user management
├── icons/
└── screenshots/

Status

Working and in personal use. The proxy is deployed on Render and CI runs on every push to main. Built as a portfolio project; not published to the Chrome Web Store.

License

MIT — see LICENSE.