We are seeking a highly skilled

Browser Extension Developer with expertise in

Core

JavaScript , contemporary frameworks. The ideal candidate should have strong

Object-Oriented Programming (OOP) skills , adhere to

SOLID principles , and have a deep understanding of browser extension development across multiple platforms (Chrome, Firefox, Edge).

The role involves designing and developing scalable browser extensions, implementing authentication mechanisms (JWT, OAuth, SSO), and ensuring secure, high-performance applications. You will work closely with backend services built using

Flask, Django , or similar frameworks, requiring an in-depth knowledge of

HTTP(s) protocols, authentication workflows, and security best practices .

Key Responsibilities: Develop, enhance, and maintain cross-browser extensions with a scalable architecture. Design modular, testable, and maintainable code following

SOLID and

OOP best practices. Implement authentication mechanisms such as

JWT, OAuth, SSO , and manage session security. Ensure deep integration with browser APIs ( Storage, Messaging, Web Navigation, WebRequest, WebAuthn ). Optimize extension performance for modern web environments (Single Page Applications, multi-frame handling). Work with backend systems

(Flask/Django) to build APIs, handle data securely, and ensure smooth communication between frontend and backend. Develop and implement security measures against XSS, CSRF, CORS, and other web vulnerabilities. Debug and troubleshoot issues across different browsers and platforms. Collaborate with cross-functional teams to design and implement new features. Stay updated with the latest browser and web technologies,



ensuring compliance with extension store policies.

Required Skills & Qualifications: Strong expertise in JavaScript, TypeScript , and modern JS frameworks (React, Vue, or similar). Expert-level knowledge of browser extension development

(Chrome, Firefox, Edge APIs). Solid understanding of

OOP, SOLID principles, and design patterns . Robust experience with

HTTP(s) protocols, RESTful APIs, WebSockets , and request handling. Hands-on experience with authentication mechanisms

(JWT, OAuth 2.0, OpenID Connect, SAML, SSO). Experience working with backend frameworks

(Flask, Django) and integrating APIs with frontend applications. Knowledge of browser security models and handling

CORS, SameSite cookies, and Content Security Policy (CSP) . Experience with debugging tools like Chrome DevTools, browser profiling, and network tracing. Familiarity with state management

(Redux, Vuex) and event-driven architectures. Strong debugging and problem-solving skills in cross-browser environments. Knowledge of build tools

(Webpack, Vite, Babel) and CI/CD pipelines. Experience working with databases (PostgreSQL, MongoDB, Redis)

is a plus. Excellent communication skills and ability to work in a collaborative environment.

Preferred Qualifications: Experience with service workers, background scripts, and content scripts in browser extensions. Understanding of identity federation , OAuth flows in enterprise environments, and SAML authentication. Familiarity with

WebAuthn for passwordless authentication. Experience in automated testing for browser extensions (Jest, Puppeteer, Playwright).

Write to me @ [email protected]

📌 Browser Extension Developer - Cybersecurity startup focused on developing cutting-edge solutions (Mumbai)
🏢 CareerXperts Consulting
📍 Mumbai