As a Senior Firmware Engineer, you will lead development on the core firmware of an open-source Bitcoin hardware wallet, contributing directly to the advancement of secure self-custody solutions. Working within a lean, high-impact team, you'll design and implement critical features that operate efficiently in tightly constrained embedded environments.
Key Responsibilities
- Develop and maintain secure, reliable firmware in C and Python for microcontroller-based devices, with a focus on the ESP32 and ESP32S platforms.
- Implement and optimize support for modern Bitcoin signing protocols, including Taproot, atomic swaps, and Simplicity.
- Design and integrate secure communication methods, such as air-gapped camera-based signing, cryptographic primitives, and hardened data exchange protocols.
- Optimize performance and memory usage to meet strict hardware limitations while maintaining robust security.
- Collaborate in a transparent, open-source development model, where all code is publicly reviewed and accessible to the broader Bitcoin community.
Qualifications
- Proven experience developing firmware in C/C++ for microcontrollers, particularly on ESP32-series chips.
- Strong grasp of Bitcoin transaction formats, including SegWit, PSBTs, and Taproot signing logic.
- Background in embedded security, including secure boot, memory protection, and defenses against software and side-channel attacks.
- Familiarity with low-level hardware interfaces such as SPI, I2C, and UART, as well as peripheral integration (e.g., displays, cameras).
- An active open-source presence, especially in security-critical or Bitcoin-related projects, is highly valued.
Preferred Background
- Experience collaborating in remote, distributed teams.
- Proficiency in Python for testing frameworks and development tooling.
- Up-to-date awareness of Bitcoin protocol developments and Layer 2 innovations.
- Exposure to Liquid Network, Elements, or confidential transaction technologies.
Environment
The team operates with a strong commitment to transparency, security, and technical excellence. You'll work in a fully remote, globally distributed setting, contributing to a project that empowers users with full control over their Bitcoin holdings. Your work will directly influence the future of decentralized finance infrastructure.
