Requirements:

7+ years of professional development experience with at least 2+ years in a Senior Software Engineer role.
3+ years of mobile development experience with native languages such as Swift and a deep understanding of mobile app architectures and patterns.
Proven ability to deliver and maintain complex software projects, ensuring quality, scalability, and reliability throughout the software development lifecycle.
Strong understanding of security practices, including data encryption, secure storage, app signing, and addressing vulnerabilities in mobile platforms.
Advanced proficiency with version control systems (e.g., Git) and experience working in a collaborative environment.
Strong attention to detail, with excellent learning and exploration skills and a product-focused mindset that looks beyond the code to consider user needs and business goals.
Deep respect for diverse skills and perspectives, with an ability to collaborate effectively across technical and non-technical teams.
Excellent English written and verbal communication skills, with the ability to clearly and concisely engage with an international, geographically distributed team.

What you'll be doing:

Build and refine Thunderbird’s mobile products and platform architecture, ensuring scalability, performance, reliability, and user-centered design.
Develop a deep understanding of the codebase and architecture to confidently make changes across the entire stack.
Develop and maintain strong debugging and testing practices, utilizing unit, integration, and automated testing frameworks to ensure software quality and reliability.
Conduct thorough code reviews and provide guidance on architectural improvements, test integration and development best practices.
Independently resolve technical challenges, including performance bottlenecks, security vulnerabilities and cross-platform integration.
Monitor application vitals and identify potential issues before they escalate.
Document technical decisions, systems architecture, and team processes to ensure transparency, maintainability, and knowledge transfer.
Own assigned projects, collaborating cross-functionally to investigate, plan, develop, validate, and deliver within established project timelines.
Work directly with users and contributors to gather information to reliably reproduce bugs and then fix them.
Ensure compliance with accessibility, security, and privacy standards in mobile development.
Leverage analytics and user feedback to inform and improve mobile user experiences.
Mentor and guide community contributors, enabling their active participation and long-term involvement in our efforts.

Familiarity with app store guidelines (Google Play Store, Apple App Store) for ensuring compliance when preparing apps for release.
Expertise in cross-platform frameworks like Kotlin Multiplatform or Rust.
Proficiency in Android application architecture and differences between iOS and Android development.
Experience contributing to open-source projects or engaging with open-source communities.
Proficiency in one of the top languages Thunderbird is translated to, such as French, German, or Japanese.