Senior Web Compatibility Engineer

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Web Compatibility Engineer based in Canada. This is a senior engineering role focused on making websites work reliably across modern browser environments and platforms. You’ll investigate complex compatibility issues and determine whether they originate from websites, browsers, or privacy protections. The role combines deep web expertise, reverse engineering, debugging, incident response, and durable engineering fixes. You’ll work across Mac, Windows, iOS, and Android to improve the browsing experience for millions of users. You’ll also help automate webcompat investigations and develop intelligent tooling that increases the team’s impact. The environment is remote-first, highly autonomous, and built around end-to-end ownership of complex technical projects. This is an opportunity to influence browser reliability while solving challenging problems at the intersection of the open web, privacy, and software engineering. Accountabilities - Own web compatibility triage, investigating and resolving complex issues that prevent websites from functioning correctly across browser platforms. - Reverse-engineer third-party and obfuscated JavaScript, isolate root causes, and reduce difficult problems to minimal, reproducible test cases. - Determine whether breakage is caused by website implementation, browser behavior, or privacy-protection features, and identify the appropriate technical solution. - Lead response to high-impact website compatibility incidents, coordinating investigation, communication, and resolution with relevant technical and non-technical stakeholders. - Design and ship durable compatibility fixes across Mac, Windows, iOS, and Android while considering differences between browser engines and system webviews. - Develop browser API shims and other technical solutions that allow websites to function consistently across supported environments.

- Identify opportunities to automate repetitive webcompat work and contribute to LLM- or agent-based tooling for reproducing, diagnosing, and triaging website issues. - Contribute to related engineering initiatives designed to improve browser reliability, reduce user friction, and strengthen long-term product engagement. - Take ownership of complex and ambiguous projects from scoping through implementation, deployment, and post-launch evaluation with minimal oversight. Requirements - 7+ years of experience building and debugging complex web applications using vanilla JavaScript. - Deep knowledge of web standards, web components, browser APIs, and the underlying behaviors that affect modern web compatibility. - Advanced reverse-engineering skills, including the ability to analyze obfuscated third-party code and isolate problems into minimal test cases. - Strong debugging and root-cause analysis skills, with a genuine interest in investigating difficult and elusive technical issues. - Experience with one or more additional technologies such as Swift, Kotlin, C#, C++, or Python is an advantage. - Experience shipping software beyond traditional web applications, including native or desktop clients. - Demonstrated experience triaging technical issues, participating in or leading incident response, and communicating effectively with stakeholders across technical backgrounds. - Interest in automation, AI-assisted development, and agentic tooling that can improve engineering efficiency and multiply team impact. - Ability to lead technically complex, ambiguous initiatives independently and make sound decisions with limited direction. - Strong written and verbal communication skills, combined with a collaborative and ownership-oriented mindset. Benefits - Annual compensation: $178,500 USD, plus stock options.