Sr Engineering Manager, Web Apps

Why Thunderbird?

Thunderbird is one of the world’s most trusted open-source email applications, empowering more than 20 million people globally. At MZLA, the team behind Thunderbird, we build privacy-respecting communication and productivity tools that help people manage their digital lives while staying in control of their data.

We are open source by design. Our products are developed transparently and in collaboration with a global community of contributors, and that same spirit shapes how we work: collaboratively, inclusively, and with a shared commitment to putting users first.

We are a small but growing company of 60+ people distributed across seven countries. As Thunderbird evolves beyond a single desktop application, we are expanding across desktop, mobile, paid services, and new product experiences that help people and organizations work more effectively without giving up control to big tech ecosystems.

Our revenue model combines user donations, which help keep Thunderbird’s apps freely available, with paid services that cover the costs of hosted offerings while supporting long-term sustainability and continued innovation.

A note about MZLA and Mozilla: MZLA Technologies Corporation is the nonprofit-owned company behind Thunderbird and part of the Mozilla family. MZLA is separate from Mozilla Corporation and has its own compensation programs, benefits, and employment policies.

To learn more, visit www.thunderbird.net

The opportunity

Thunderbird is growing beyond our free desktop and mobile applications, and we’re looking for a Senior Manager, Web Applications to lead day-to-day engineering execution and people management for the team responsible for MZLA’s hosted subscription products.

This is a critical product and revenue area for MZLA. The Senior Manager will help the team launch, maintain, and improve hosted services with strong delivery discipline, clear ownership, reliable engineering practices, and a continued focus on quality, privacy, reliability, and user trust.

This is a small, growing team, and the right person will be a hands-on technical manager who wants to stay close to the codebase, product direction, service reliability needs, release readiness, and engineering tradeoffs while also leading people and improving how the team operates. As the Web Applications team continues to mature, this role will require an engaged manager who can help create structure, solve problems, support execution, and build stronger systems around the work.

This role requires consistent overlap with EST time zone working hours, and we strongly prefer candidates located in or closely aligned with this time zone.

What you’ll do 

• Lead day-to-day engineering execution in a hands-on management capacity, ensuring priorities, ownership, timelines, risks, dependencies, and quality expectations are clear.
• Manage Web Services engineers and contractors, including coaching, feedback, prioritization, performance support, and team development.
• Manage team budget and resource planning, including contractor, vendor, tooling, service, operational expense, and headcount planning inputs.
• Translate product direction, technical priorities, and organizational needs into coordinated engineering plans.
• Establish team processes, workflows, planning practices, and operating rhythms that improve clarity, accountability, quality, and predictability.
• Maintain enough product and architectural context to evaluate tradeoffs, identify risks, and manage engineering work credibly.
• Improve engineering practices related to code review, testing, documentation, release readiness, observability, technical debt, and operational readiness.
• Coordinate launch and operational readiness across technical and cross-functional partners.
• Communicate progress, priorities, risks, and decisions clearly to stakeholders while fostering an engineering culture grounded in accountability, inclusion, technical quality, open-source values, and continuous improvement.

What you bring 

• 15+ years of overall industry experience, with at least 10 years of engineering leadership experience in software product, hosted services, SaaS, cloud-based applications, communications platforms, or similarly complex technical environments.
• 5+ years of people management experience in an engineering environment, including coaching, feedback, prioritization, performance support, career development, and team development.
• Experience managing senior technical teams, team budget and resource planning, and partnerships with directors, senior ICs, product stakeholders, infrastructure/SRE teams, contractors, external partners, and cross-functional stakeholders.
• Experience translating technical, product, or organizational direction into clear execution plans, ownership models, delivery practices, operating rhythms, and measurable outcomes.
• Technical depth sufficient to understand engineering tradeoffs, release risks, codebase quality, architectural implications, service reliability, security/privacy considerations, operational readiness, and engineering practices such as code review, testing, documentation, observability, CI/CD, incident learning, and technical debt management.
• Strong communication and relationship-building skills, with the ability to create clarity, accountability, and follow-through in small, scaling, ambiguous, or evolving environments.
• Demonstrated ability to thoughtfully evaluate and integrate AI-enabled tools into engineering management practices, team workflows, decision-making, and productivity improvements, while setting clear expectations around accuracy, privacy, security, and responsible use.

Bonus points for

• Experience with hosted email, calendaring, scheduling, secure file sharing, communications platforms, or related subscription products.
• Experience with identity systems, billing/subscription integrations, customer lifecycle workflows. 
• Experience working in open-source or maintainer-style engineering environments.
• Experience with privacy-preserving product design, data minimization, security reviews, compliance needs, or user-controlled systems.

What success looks like

Within the first year, success means the Web Applications team is operating with clear ownership, strong delivery predictability, and effective coordination across employees, contractors, contributors, and cross-functional partners. Planning, reviews, launches, and ongoing operations should be disciplined and reliable, supported by engineering practices that help the hosted subscription portfolio mature with quality, privacy, reliability, and user trust.

Work environment

You’ll work with our passionate staff and open-source community members from all over the globe to support the mission and objectives of MZLA. 

This is a remote, full-time position. Strong communication and documentation skills are essential for effective collaboration across time zones and disciplines.

Compensation & benefits

We benchmark our base salaries to local markets and target the 60th percentile of the peer market. The salary ranges for this role are:

• US: $175,000 - $200,000 USD

We may consider candidates with strong skills but less than the required experience. Compensation will be determined based on qualifications and experience.

In addition to competitive salaries, we offer a comprehensive benefits package designed to support your whole self.

Work & career

• Fully remote work & schedule flexibility
• Company-provided laptop
• Annual bonus program
• Monthly remote work stipend
• Annual professional development stipend
• Industry conferences
• Company all-hands and team gatherings

Rest & play

• 24 days PTO per year (prorated) 
• Your birthday
• Year-end company shutdown
• 9 wellbeing days 
• Public holidays
• Other paid leave
• Quarterly wellbeing stipend for personal / family activities

Health & family

• 401(k) contributions
• Health, dental, & vision insurance
• Disability insurance
• Life insurance
• Employee assistance program 
• Paid parental leave
• Paid sick days 

Work eligibility

Applicants must reside in and have permanent work authorization for the country location(s) specified in the posting. We are unable to consider applicants outside of these markets at this time. And, we do not provide visa sponsorship.

How to apply

Please apply directly through our career page. We carefully review every cover letter and screening question, so take the time to answer each fully. We value authentic, thoughtful responses that reflect your own experience and perspective. It is fine to use AI tools to polish your writing, but your answers should be your own. Candidates who submit generic or unoriginal AI-generated responses may be disqualified from further consideration.

Our commitment to diversity, equity, and inclusion

MZLA believes in the value of diverse creative practices and forms of knowledge, and knows diversity, equity and inclusion are crucial to and enrich the company’s core mission. We encourage applications from everyone, including members of all equity-seeking communities, such as (but not limited to) women, racialized and Indigenous persons, persons with disabilities, persons of all sexual orientations, gender identities and expressions.

We are an equal opportunity employer. We do not discriminate on the basis of race (including hairstyle and texture), religion (including religious grooming and dress practices), gender, gender identity, gender expression, color, national origin, pregnancy, ancestry, domestic partner status, disability, sexual orientation, age, genetic predisposition, medical condition, marital status, citizenship status, military or veteran status, or any other basis covered by applicable laws. MZLA will not tolerate discrimination or harassment based on any of these characteristics or any other unlawful behavior, conduct, or purpose. 

We will ensure that qualified individuals with disabilities are provided reasonable accommodations to participate in the job application or interview process, to perform essential job functions, and to receive other benefits and privileges of employment, as appropriate. Please contact us at [email protected] to request accommodation.

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