Job Openings Senior Android Engineer

About the job Senior Android Engineer

About Ledger

Founded in 2014, Ledger is the global platform for digital assets and Web3. Over 20% of the world's crypto assets are secured through our devices — with more than 7.5 million hardware wallets sold across 200 countries.

We're on a mission to make self-custody accessible and give people the keys to their own financial futures. With a team of 600+ professionals across Paris, London, Singapore, and beyond, we build hardware and software that enables individuals and institutions to securely buy, store, swap, and grow their crypto assets.

We believe change is constant and our team moves forward as one — with a culture of problem-solving where every engineer is empowered to challenge tradition and push the limits of what's possible.

The Role

We're building the next generation of Ledger devices: a custom Android-based product that puts secure digital asset management directly in users' hands. This is a greenfield Android application project (you'll be writing system apps, and user-facing experiences that run on a bespoke AOSP-based device, developed in close collaboration with firmware and hardware engineers).

This isn't feature-factory work. You'll co-own the product alongside Design, Product, and cross-functional tech teams, with full ownership from architecture to production (on a device that genuinely doesn't exist yet).

What You'll Work On

  • Design and build the Android applications that power this new device: onboarding flows, asset management interfaces, and system-level UX
  • Own features end-to-end (from technical design and implementation through QA, release, and impact measurement)
  • Work alongside firmware and hardware engineers to define interfaces between the application layer and the underlying platform
  • Collaborate with the Ledger Wallet team (React Native) to ensure a consistent experience across our product ecosystem
  • Contribute to architecture decisions, define the app tech stack, and raise the engineering bar through reviews and mentoring
  • Never compromise on security and quality (you're building software that users trust with real financial assets) LEDGER Confidential

Tech Stack

Kotlin · Jetpack Compose · Coroutines / Flow · Jetpack Architecture Components · Dependency Injection (Hilt/Koin) · CI/CD · AOSP (context, not daily work)

Required Skills & Experience

  • 6+ years of Android development with strong mastery of modern architectures (MVVM, MVI) and engineering best practices
  • Fluent in Kotlin, with solid experience in Coroutines/Flow and Jetpack Compose
  • Strong grasp of Clean Architecture and SOLID principles (you apply them pragmatically, not dogmatically)
  • Comfortable working at the intersection of application and platform layers (you understand what lies beneath your code even if you don't write it every day)
  • Track record of shipping polished, production-grade Android apps with attention to performance, animations, and UX quality
  • Product mindset: you make decisions based on user impact and data, not just technical elegance
  • Strong communicator (able to work cross-functionally with Design, Product, QA, and embedded engineering teams)
  • Experienced with good engineering practices: unit testing, CI/CD, code reviews, documentation
  • AI-proficient: you actively leverage AI tools (GitHub Copilot, Cursor, LLM assistants) to move faster, debug smarter, and sharpen the quality of your output

Nice to Have

  • Familiarity with AOSP (understanding the build system, system applications, or Android framework customization is a real asset given the project context)
  • Experience with React Native (Ledger Wallet (our companion app) is built in React Native; cross-platform context helps you understand the broader ecosystem you're building for)
  • Knowledge of the Web3 / blockchain space (wallets, transaction signing, key management)
  • Background in cryptography or security: secure storage, keystore, cryptographic primitives

What We're Looking For Beyond the CV

  • You take ownership seriously (when a problem falls in the grey zone, you pick it up)
  • You move fast and learn fast (this is a new product with many unknowns; you're comfortable with ambiguity)
  • You care about craft: smooth interactions, clean code, and correct security boundaries matter equally to you
  • You can work across disciplines (embedded engineers, product designers, and blockchain engineers will all be part of your day-to-day)