Software Engineer, Sr.

About The Company MZLA Technologies Corporation (MZLA) is a wholly owned, for-profit subsidiary of the Mozilla Foundation, dedicated to developing open-source email and productivity solutions. Home to Thunderbird, our flagship open-source email platform, MZLA empowers over 20 million users worldwide. Operating independently in both organizational structure and identity from Mozilla Foundation and Mozilla Corporation, we prioritize transparency, collaboration, and community-driven development. All our projects are developed openly, involving a global community of contributors, which fosters innovation and inclusivity. Our core philosophy emphasizes privacy and productivity, ensuring users retain control over their data while enjoying powerful digital tools. With a team of over 50 professionals distributed across seven countries, MZLA is evolving Thunderbird into a comprehensive suite of privacy-respecting productivity applications, including new products and services that remain independent of big tech ecosystems. Our revenue model combines community donations for free products with subscriptions for cloud-based services, enabling sustainable development focused on user needs.

About The Role We are seeking a highly skilled Senior Software Engineer, Web Services, to join our dynamic team. In this role, you will be instrumental in shaping the future of email technology by leveraging cutting-edge standards such as JMAP. Your responsibilities will include developing and maintaining scalable web services, infrastructure, and systems that extend Thunderbird beyond traditional desktop and mobile platforms. You will lead technical initiatives, influence product direction, and collaborate across geographically dispersed teams to deliver high-quality, reliable solutions. Your expertise will help optimize email delivery systems, troubleshoot complex issues, and implement improvements that enhance performance and user experience. This role offers an exciting opportunity to work on innovative open-source projects, influence product strategy, and contribute to building sustainable, privacy-focused digital tools for millions of users worldwide.

Qualifications

• 7+ years of experience in software engineering, with a focus on web infrastructure, service architecture, or DevOps.
• 2+ years of hands-on experience in email development, including configuring and maintaining email services and infrastructure.
• 5+ years of experience building and maintaining web services across the full stack, from backend development to deployment and monitoring.
• Proficiency in Python 3, with at least 2 years of practical experience.
• Proven track record of owning features from conception through delivery and ongoing maintenance.
• Excellent communication and documentation skills, with experience working in distributed, remote teams.
• Strong understanding of email authentication protocols such as DMARC, DKIM, and SPF, as well as email deliverability best practices.
• Deep respect for open-source development principles and open standards.
• Ability to collaborate effectively with multidisciplinary teams, including designers, product managers, and community contributors.
• Experience working across multiple time zones and asynchronous communication environments.

Responsibilities

• Lead and scope significant technical initiatives, including planning, prioritization, and execution of features.
• Shape product vision by advocating for user needs and contributing to long-term development roadmaps.
• Design, develop, and maintain web services primarily using Python and Typescript, ensuring scalability and performance.
• Analyze complex email delivery challenges, optimize configurations, and improve infrastructure to enhance email deliverability and reliability.
• Collaborate with global teams, including designers, engineers, and community contributors, to deliver high-quality solutions.
• Implement thorough testing, conduct code reviews, and ensure adherence to best practices for quality and security.
• Support the stability and operational excellence of services, including participation in on-call rotations when necessary.
• Stay current with industry trends, emerging technologies, and best practices to continually improve our systems and processes.

Benefits

• Fully remote work environment with flexible scheduling options.
• Competitive salary aligned with the 60th percentile of local markets, ranging from $125,000 to $145,000 USD.
• Comprehensive health, dental, and vision insurance coverage.
• Retirement plan contributions (401(k) in applicable regions).
• Paid time off including 24 days PTO, personal wellbeing days, holidays, and your birthday.
• Paid parental leave and sick days to support work-life balance.
• Work and career development stipends, including access to Udemy learning platform and industry conferences.
• Remote work stipend, professional development stipend, and a latest-generation laptop to support your productivity.
• Employee assistance program and wellbeing stipends for personal and family activities.
• Participation in company-wide all-hands meetings and team-building events.

Equal Opportunity

MZLA Technologies Corporation is committed to creating an inclusive environment and is proud to be an equal opportunity employer. We do not discriminate based on race, religion, gender, gender identity or expression, sexual orientation, national origin, disability, age, or any other protected characteristic under applicable laws. We value diversity and encourage applications from all qualified individuals, including members of underrepresented communities. Reasonable accommodations are available for applicants with disabilities throughout the hiring process. We believe that diverse teams foster innovation, creativity, and better solutions, and we are dedicated to ensuring a welcoming and equitable workplace for everyone.