Senior Full-Stack Engineer

GuruLink; Montreal; On-site; CAD 80,000 - 110,000; Full time

Job summary

A Montreal startup is seeking a Senior Full Stack Developer to optimize their AI-driven affiliate platform. You will focus on improving browser script performance and maintaining the embedded tech stack. Candidates should have extensive experience in JavaScript and TypeScript, strong knowledge of browser internals, and familiarity with Node.js. This role offers a unique opportunity to contribute to innovative revenue streams for digital audiences.

Qualifications

• Extensive experience in JavaScript (vanilla and ES6+) and TypeScript.
• Strong understanding of browser internals, including event loop and rendering pipeline.
• Proficient in Node.js for backend development and web scrapers.
• Solid grasp of HTTP, REST/JSON, and proxy behavior.
• Familiarity with browser fingerprinting techniques and session management.

Responsibilities

• Optimize browser script performance with strategies like minification and lazy loading.
• Develop mechanisms to inject widgets into various websites.
• Build client-side logic for reliable user interactions.
• Create and maintain Node.js and Python-based scrapers.
• Troubleshoot runtime logic for conflicts in live environments.
• Own and maintain the entire embedded stack including scripts and APIs.

Skills

JavaScript (vanilla and ES6+)

TypeScript

Node.js

Browser internals

HTTP/REST/JSON

Open-source contributions

Python

Education

Bachelor’s or Master’s in Computer Science

Tools

Node.js

Python

Job description

Location: Montreal, Quebec

Our client is a homegrown Montreal startup. They are transforming the way digital audiences convert online. Their AI-driven affiliate platform empowers publishers, ticketing providers, and content creators to unlock new revenue streams while enhancing user experience. By delivering smarter monetization tools, their partners don't just earn more, they deliver more.

They are currently looking for a Senior Full Stack Developer to join the Phantom squad. In this role, you'll work at the core of their embedded widget and affiliate tech, focusing on optimizing script performance across diverse web environments. You'll lead efforts to streamline browser execution, build privacy-conscious session tracking systems, and maintain the full lifecycle of embeddable scripts and SDKs. This is a highly technical role with a strong emphasis on real-world performance, reliability, and robustness.


You will:
•Improve browser script performance by implementing optimization strategies such as minification, caching, and lazy loading.
•Develop mechanisms to inject widgets and content into a wide range of websites, handling dynamic DOM structures and layout changes.
•Build client-side logic to track and capture user interactions reliably and efficiently.
•Design and integrate fingerprinting techniques for cross-domain session tracking with privacy-conscious approaches.
•Create and maintain Node.js- and Python-based scrapers for data collection and fallback systems to ensure resilience and continuity.
•Troubleshoot and refine runtime logic for edge cases and third-party script conflicts in live environments.
•Own and maintain the entire embedded stack—scripts, SDKs, APIs—and collaborate cross-functionally to deploy new features and updates smoothly.

Must Have Skills:

•Extensive experience working directly with JavaScript (vanilla and ES6+) and TypeScript, without reliance on frontend frameworks (e.g., no React or Vue for core functionality).
•Strong understanding of browser internals, including the event loop, DOM/CSSOM, rendering pipeline, and performance metrics such as FCP and LCP.
•Proficient in Node.js for backend development and building web scrapers;
•Solid grasp of HTTP, REST/JSON, and proxy behavior in modern web architectures.
•Understanding of browser fingerprinting techniques, session management, CORS, and privacy regulations such as GDPR is a significant asset.
•Open-source contributions or public GitHub projects are strongly preferred.
•A degree in Computer Science (Bachelor’s or Master’s)

Nice to Have Skills:

•Familiarity with Python scraping frameworks is a plus.