Principal Mobile Engineer, Platform

About the role

This Principal Mobile Engineer role focuses on the MetaMask Mobile platform, a key product within Consensys's Web3 ecosystem. The work involves defining and evolving the platform's architecture, making critical trade-offs between JavaScript/TypeScript, React Native, and native components to optimize performance and development speed. Core responsibilities include designing and stewarding platform systems such as over-the-air updates, analytics foundations, and data persistence, ensuring a robust and efficient mobile experience.

A significant part of this position involves leading high-impact, cross-team initiatives. This includes driving major upgrades, migrations of foundational libraries, and structural performance improvements related to startup time, crash rates, and memory usage. The engineer will also focus on elevating the developer experience by improving tooling, build/test pipelines, and release workflows, aiming for automation and reduced operational burden for all mobile engineers.

Success in this role means not only delivering technical excellence but also multiplying impact through leadership and mentorship. The Principal Engineer will mentor senior engineers, influence technical direction across the Wallet Platform and MetaMask, and contribute to shaping the hiring and technical culture of a lean, senior Mobile Platform team. This position requires a strong focus on app health and performance, defining metrics, and providing tools for feature teams to self-diagnose and own regressions.

The salary range for this position for US-based candidates is between $227,000 and $272,000 USD, not including bonus, equity, or other benefits.

Skills that matter here

• React Native: This role requires deep expertise in React Native for architectural decisions, performance tuning, and debugging within a large-scale production environment.
• iOS: Experience with native iOS development, including Swift, is necessary for understanding and optimizing native modules and performance.
• Android: Familiarity with native Android development, including Kotlin, is important for addressing native aspects and performance tuning.
• Swift: Knowledge of Swift is applied when working with native iOS components and bridging between React Native and the native platform.
• Kotlin: Understanding Kotlin is relevant for optimizing native Android elements and ensuring seamless integration with the React Native platform.

Who this role suits

• A mobile engineer with over a decade of experience building and scaling complex mobile applications.
• Someone who has previously operated at a Staff or Principal level, leading multi-team technical initiatives.
• An individual who excels at influencing technical direction and mentoring other engineers, even without direct authority.
• A person comfortable navigating ambiguity and designing durable, reusable solutions for internal platforms and tools.

From the employer

As a Principal Engineer, you will:

• Own mobile platform architecture
• Define and evolve the architecture of MetaMask Mobile (React Native + native).
• Make key tradeoffs between JS/TS, RN, and native to balance performance, reliability, and iteration speed.
• Design and steward core platform systems (e.g., OTA, analytics foundations, data/persistence, auth, VPN/geolocation primitives).
• Lead high‑impact, cross‑team initiatives.
• Drive large upgrades and migrations (React Native, navigation, foundational libraries).
• Lead structural performance and stability work: startup time, crash rate, ANRs, jank, memory usage, bundle size.
• Break large efforts into incremental, shippable milestones with clear impact.
• Elevate developer experience & automation.
• Improve tooling, local dev ergonomics, build/test pipelines, and release workflows for all mobile engineers.
• Establish clear patterns for navigation, state management, and platform primitives to reduce cognitive load.
• Push towards “push‑button” releases and reduced operational toil via automation.
• Build an AI‑enabled platform.
• Integrate AI/LLMs into workflows to scaffold code, enforce patterns, and improve testing and feedback loops.
• Help define how tickets and platform patterns leverage AI safely and effectively.
• Drive app health & performance culture.
• Define and evolve metrics and dashboards for performance, stability, and efficiency.
• Provide tools and guidance so feature teams can self‑diagnose and own regressions.
• Champion shared accountability for app health across all teams contributing to mobile.
• Multiply impact through leadership.
• Mentor Senior/Staff engineers and influence technical direction across Wallet Platform and MetaMask.
• Lead design and architecture reviews for critical platform areas.
• Help shape hiring and technical culture for a lean, senior, high‑leverage Mobile Platform team.

Would be great if you brought this to the role:

Experience:

• 10+ years building and scaling mobile apps, including ownership of large, production React Native or hybrid mobile platforms.
• Prior Staff/Principal‑level impact: leading complex, cross‑team technical initiatives.

Technical depth:

• Deep expertise with React Native in production: architecture, performance, debugging, bridging.
• Solid experience with native iOS (Swift/SwiftUI) and/or Android (Kotlin/Jetpack), including native modules and performance tuning.
• Strong understanding of mobile CI/CD, release engineering, and OTA systems.

Platform & systems mindset

• Track record building internal platforms, shared libraries, or tooling for other engineers.
• Comfort operating in ambiguity and designing durable, reusable solutions.
• Strong architecture and communication skills; able to align diverse stakeholders.

Leadership & mentorship:

• Proven ability to influence without authority, set technical direction, and raise the engineering bar.
• Experience mentoring senior engineers and shaping technical culture.

AI‑curious / AI‑pragmatic

• Experience or strong interest in using AI/LLMs to improve developer productivity and code quality.

We’re passionate about building a diverse team of humans and as such, if you think you've got what it takes for our chaotic-but-fun, remote-friendly, start-up environment—apply anyway, detailing your relevant transferable skills in your cover letter.

• The salary range for US-based candidates only will be determined throughout the interview process depending on experience and skills.
• US pay range (not including bonus, equity or other benefits) $227,000—$272,000 USD.