User Interface​/Visual Designer

MZLA Technologies Corporation (MZLA) is a wholly owned, for-profit subsidiary of the Mozilla Foundation and home to Thunderbird , our flagship open-source email and productivity platform empowering more than 20 million people around the world. While part of the Mozilla portfolio of companies, MZLA operates independently in both identity and organizational structure from the Mozilla Foundation and Mozilla Corporation.

Everything we build at MZLA is open source, developed transparently and in collaboration with a global community of contributors. This open approach shapes not only our products but also how we work: collaboratively, inclusively, and with a shared commitment to building technology that puts users first. We believe privacy and productivity should coexist , and that people deserve powerful digital tools without surrendering control of their data.

MZLA is a small but growing team of 50+ people distributed across seven countries . As we evolve Thunderbird from a single application into a suite of privacy-respecting productivity tools, we’re introducing new products and services that remain independent of big tech ecosystems . Our unique revenue model combines community donations that keep Thunderbird freely available with subscriptions for new cloud-based services, allowing us to grow and innovate while remaining independent and true to our values.

As a User Interface / Visual Designer, you’ll help shape and refine the visual language of our desktop, web, and mobile platforms, creating cohesive, accessible, and visually compelling interfaces that express our brand and support intuitive interaction. You’ll join the Design team, which works across Thunderbird and MZLA to deliver high-quality, user-focused experiences.

You’ll work closely with design and front-end development teams to take projects from concept to delivery, translating requirements into layouts, design systems, components, and production-ready assets. You’ll thrive in this role by bringing strong visual craft, a commitment to accessibility and consistency, and a track record of accountability, follow-through, and thoughtful problem-solving, while comfortably driving work forward with support from teammates.

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You’ll play a vital part in delivering polished, intuitive experiences for our global user community and owning medium-sized projects. This is a full-time, remote position working with colleagues across multiple regions and time zones.

What you’ll do:

• Create and refine high-fidelity layouts and UI components.
• Build interactive prototypes, starting from low-fidelity wireframes when needed.
• Deliver visually appealing, accessible interfaces aligned with user needs and brand guidelines.
• Translate designs into implementation-ready specifications and assets.
• Account for responsive behaviour, typography, colour contrast, spacing, and accessibility across platforms.
• Work within and contribute to design systems, component libraries, and style guides.
• Apply information hierarchy, layout, and interaction design to create clear, readable interfaces.
• Identify and articulate visual design issues, extract insights from feedback, and propose design solutions in collaboration with cross-functional partners.
• Support UX research activities by preparing visual assets, participating in studies and applying research findings to visual and interaction details.
• Engage with the open-source community to gather feedback and foster collaboration.
• Support ad hoc projects as required.

What you’ll bring:

• 3+ years of professional experience in user interface / visual design or a closely related role, with increasing responsibility and a proven ability to scope and finish projects.
• A strong portfolio demonstrating high-fidelity layouts, UI components, and prototypes for web, desktop, and/or mobile products, with clear design rationale and impact.
• Experience working on multi-platform products and contributing to scalable design systems, component libraries, and style guides.
• Familiarity with accessibility standards (e.g. colour contrast, typography, motion) and applying them to create inclusive, usable interfaces.
• Bachelor’s degree or equivalent experience in design,…