Senior Full-Stack Engineer, Email Systems

MZLA Technologies Corporation is a subsidiary of the Mozilla Foundation focused on developing the Thunderbird email and productivity platform. The Senior Full-Stack Engineer will contribute to a suite of communication tools, focusing on web development, infrastructure, and service architecture, while collaborating with various teams to enhance user-facing features.

Responsibilities:

• Build 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

Requirements:

• 7+ 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
• Background 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