JavaScript Developer with Chrome extension experience

We’re looking for a talented developer to join our team on a part-time or project basis to help build out Karboard, a Chrome extension designed to streamline workflows inside Karbon (an accounting practice management platform). You’ll be working on custom keyboard shortcuts, a collapsible sidebar UI, DOM inspection tools, and integrations with APIs like Karbon, Firebase Auth, Firestore, and Stripe.

???? Key Responsibilities

1. Develop and maintain a custom Chrome extension with a focus on usability and performance.
2. Implement keyboard shortcuts mapped to UI buttons via Shadow DOM traversal.
3. Build a collapsible sidebar using React + Tailwind, displaying contextual data.
4. Implement Firebase Authentication (email/password) for user access control.
5. Use Firestore to manage feature access and subscription status.
6. Integrate with Stripe for billing and feature gating (via subscription plans).
7. Integrate and use PostHog to log user actions and errors.
8. Optimize extension performance and handle edge cases (e.g., Karbon DOM changes, offline handling).
9. Write clean, maintainable code and document components for future development.

???? Tech Stack
The ideal candidate should be comfortable with:

Must-Have:

1. JavaScript (ES6+)
2. Chrome Extension APIs (Manifest V3)
3. React (with Tailwind CSS)
4. Firebase (Auth, Firestore)
5. Stripe API (Basic subscription billing, webhook handling)
6. DOM Manipulation and Shadow DOM traversal (important for Karbon)
7. Git and GitHub for version control

Nice-to-Have:

1. TypeScript
2. Puppeteer or Chrome DevTools Protocol knowledge (for inspection/emulation)
3. PostHog or similar analytics tooling
4. Experience building tools for SaaS or B2B workflows
5. Understanding of accounting firm workflows (not required, but a plus!)

???? Preferred Qualifications

1. Proven experience building and publishing Chrome Extensions
2. Ability to write modular, testable, and well-documented code
3. A strong eye for UX/UI (especially with productivity tools)
4. Self-starter with good communication skills — async-friendly via Slack and Notion
5. Bonus: Experience with Karbon or similar platforms (e.g., ClickUp, Asana, Notion integrations)

???? Scope of Work
Start with these deliverables (can grow over time):

1. Implement various keyboard shortcuts for Karbon UI actions
2. Add collapsible sidebar instead of extension popup.
3. Implement slash command-based snippet functionality.
4. Implement headless functionality in collapsible sidebar to pull in different information based on the page a user is looking at while using Karbon.
5. Set up Firebase Auth & Firestore subscription management
6. Integrate Stripe billing with feature gating
7. Build an analytics + error logging mechanism

???? Hours & Engagement

1. Flexible hours, project-based with potential for ongoing work
2. Timezone: Ideally North America, but async collaboration is fine
3. Expected availability: To discuss.

???? Compensation

1. Open to structured milestone payments, hourly, fixed fee. Let's discuss.

?? How to Apply
Please include:

1. GitHub or portfolio of Chrome Extensions you've worked on
2. A short note about why this type of tool interests you
3. Your availability and preferred engagement model (part-time, project, hourly, etc.)