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 Kotlin and frameworks such as Jetpack Compose.
Proven ability to deliver and maintain complex software projects, ensuring quality, scalability, and reliability throughout the software development lifecycle.
Demonstrated interest in building software that runs on multiple platforms, with an understanding of the associated challenges and trade-offs.
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.
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.

Nice to Haves

Familiarity with app store guidelines (Google Play Store, Apple App Store) for ensuring compliance when preparing apps for release.
Hands-on experience developing cross-platform applications using Kotlin Multiplatform, Rust, or similar frameworks.
Proficiency in iOS 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.

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.
Conduct thorough code reviews and provide guidance on architectural improvements.
Independently resolve technical challenges, including performance bottlenecks and security vulnerabilities.
Monitor application vitals and identify potential issues before they escalate.
Document technical decisions, systems architecture, and team processes.
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.