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Senior Mobile Engineer, iOS

Mozilla· Thunderbird
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Hybrid (Canada)CA$108k - CA$125kfull-timePosted 2mo ago

About the role

Senior iOS-focused software engineer responsible for designing, developing, and evolving Thunderbird’s iOS app, ensuring performance, reliability, accessibility, security, and maintainability, while collaborating with cross-functional teams and open-source contributors.

Responsibilities

  • - Build and refine Thunderbird’s mobile products and platform architecture.
  • - Improve scalability, performance, reliability, and user experience.
  • - Develop a deep understanding of the codebase and architecture to confidently make changes across the entire stack.
  • - Maintain strong debugging and testing practices across unit, integration, and automated testing.
  • - Review code and guide improvements to architecture, testing, and development best practices.
  • - Independently resolve complex issues involving performance, security, and cross-platform integration.
  • - Monitor application health and address issues before they escalate.
  • - Document technical decisions, system architecture, and team processes.
  • - Own assigned projects, collaborating cross-functionally, from investigation and planning through development, validation, and delivery.
  • - Ensure mobile development meets accessibility, security, and privacy standards.

Qualifications

  • 7+ years of professional software development experience, including 2+ years in a Senior Software Engineer role.
  • 3+ years of professional mobile application development experience.
  • Strong experience with Swift, SwiftUI, and iOS frameworks.
  • Deep knowledge of iOS architecture, design patterns, and performance optimization.
  • Experience delivering and maintaining complex, scalable, and reliable software.
  • Experience addressing technical debt and refactoring large or complex codebases.
  • Strong knowledge of mobile security, including encryption, secure storage, app signing, and vulnerability remediation.
  • Experience with communication and email protocols such as RSS, IMAP, POP, or Matrix, and familiarity with the IETF standards for CalDav or CardDav.
  • Advanced proficiency with Git and collaborative development workflows.
  • Strong debugging, testing, and problem-solving skills.
  • Strong attention to detail, curiosity, and a product-focused mindset.
  • Ability to work independently, take ownership, and collaborate across teams.
  • Respect for diverse skills, experiences, and perspectives.
  • Excellent async written communication skills; comfortable working with a geographically distributed team.
  • Ability to learn, evaluate, and responsibly use emerging technologies, including AI-enabled tools, to improve work processes.

Skills

Required:SwiftSwiftUIiOS frameworksSecurityTesting

Benefits

  • - Fully remote work & schedule flexibility
  • - Company-provided laptop
  • - Annual bonus program
  • - Monthly remote work stipend
  • - Annual professional development stipend
  • - Access to Coursera learning platform
  • - Industry conferences
  • - Company all-hands and team gatherings
  • - 24 days PTO per year (prorated)
  • - Your birthday
  • - Year-end company shutdown
  • - 9 wellbeing days
  • - Public holidays
  • - Other paid leave
  • - Quarterly wellbeing stipend for personal / family activities
  • - RRSP contributions
  • - Health, dental, & vision insurance
  • - Disability insurance
  • - Life insurance
  • - Employee assistance program
  • - Paid parental leave
  • - Paid sick days
Last updated Sep 30, 2026. Interested? Apply on the company site.

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