Senior Full-Stack Engineer, Email Systems (Remote)

The OpportunityAs a Senior Software Engineer, Web Services, you’ll contribute to a whole new suite of communication tools including end-to-end encrypted file sharing, an email service, an appointment booking service, and more. You’ll join the Web Services Team, which is responsible for building and maintaining the accounts and email services that power these offerings.The ideal candidate will have a strong focus on web development, infrastructure, and service architecture. This person has direct experience with email delivery, is autonomous, and can lead feature development from an ambiguous project statement to a concrete plan and implementation. You are passionate about delivering quality to customers and naturally think about products from the user’s perspective, always seeking ways to improve and elevate the experience.You’ll work closely with designers, engineers, and community members to develop and maintain user-facing features and help diagnose and resolve email issues at scale. The ideal candidate has strong full-stack development experience and demonstrates collaboration, ownership, and a commitment to building reliable services.What you’ll doBuild and prototype new features and solutions to tackle complex technical challenges.Develop and maintain metrics to monitor email delivery rates and sender reputation, and diagnose service-level issues.Monitor email industry standards, trends, and emerging threats, and propose improvements to strengthen delivery, reputation, and spam resilience.Develop, test, and evolve the code architecture to ensure scalability, maintainability, and robustness.Conduct code reviews to ensure adherence to quality standards and best practices, and contribute to technical strategy and architectural decision-making.Along with our designers and product leads, build and deploy prototypes and experiments to improve workflows, conversions, and privacy-respecting analytics capabilities.Evaluate and implement systems and improvements across security, logging, performance, and accessibility.Support the stability and reliability of our services, including participation in a shared on-call rotation.What you’ll bring7+ years of professional software development experience, including 2+ years in a Senior Software Engineer role.2+ years of experience with JavaScript/TypeScript and 2+ years working with Python 3.Experience building and maintaining email services.Experience building and maintaining web applications.Experience working across the full software development life cycle, from product inception through customer delivery.Deep respect for diverse skills and perspectives, with an ability to collaborate effectively across technical and non-technical teams.Ability to translate wireframes, style guides and design direction into polished, production-ready visual experiences.Proven ability to deploy and manage web infrastructure on AWS or similar cloud providers.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.Excellent English written and verbal communication skills, with the ability to clearly and concisely engage with an international, geographically distributed team.Commitment to collaboration, open development, and building secure, privacy-respecting technology aligned with Thunderbird and MZLA’s values.Bonus points forBackground in Java and/or Rust development.Familiarity with Stalwart (email server).Hands-on work developing and maintaining an Identity Provider (IdP) such as Keycloak or similar.Practice writing Infrastructure as Code (IaC), ideally with Pulumi.Contributions to open-source projects or active engagement with open-source communities.