Senior Software Engineer (Cryptography), Bitkey

Company Description
Block is one company built from many blocks, all united by the same purpose of economic empowerment. The blocks that form our foundational teams - People, Finance, Counsel, Hardware, Information Security, Platform Infrastructure Engineering, and more - provide support and guidance at the corporate level. They work across business groups and around the globe, spanning time zones and disciplines to develop inclusive People policies, forecast finances, give legal counsel, safeguard systems, nurture new initiatives, and more. Every challenge creates possibilities, and we need different perspectives to see them all. Bring yours to Block.
Job Description
Bitkey sits within the Proto team. Proto's purpose is to accelerate the world's transition to a more open economy by making products that increase access and independence for everyone. The first two initiatives we've identified that represent the biggest impact to this purpose are in the Bitcoin space with Bitcoin mining and Bitkey, a self custody Bitcoin wallet. While we're starting there, we don't believe the need for tools to increase one's independence is limited to bitcoin or the financial space. One principle across everything we do in Proto is open development - show and tell. We develop products in the open , you can read more about them at bitkey.build and mining.build.
Bitkey is looking for a staff-level engineering leader that will help guide and influence the technical direction of the software and services that will power our self-custody product. Cryptographic primitives are at the center of the software we're building to support our multi-signature wallet so we're looking for a leader who has that foundation of knowledge to help lead our technical strategy and collaborate on executing our product vision. This is a cross-cutting role that will innovate on the first version of our product and shape new product areas in the coming years.
In this role, you will:

• Design, build, deploy, and sustain a wide range of secure and reliable services supporting the wallet including multisig key management and provisioning, blockchain interaction, recovery processes, logistics, and more
• Assess risks to our customers across a wide range of product and technology areas, including mobile, backend infrastructure, key management, account recovery, third party integrations, authentication, and privacy
• Communicate clearly about risks to teammates across product, software, hardware, support, and supply chain
• Participate in our team's internal and external transparency by authoring posts and documentation accessible to a wide audience
• Make key architecture and platform choices, leveraging existing Block infrastructure and best practices where appropriate and and forging a new path when our unique needs require it
• Collaborate with engineers across of varying disciplines, product managers, and many other teams throughout the company
• Own testing, observability, and maintenance for the services you and the team create

Qualifications
You have:

• 10+ years of experience with the full lifecycle of critical production services (server or mobile). Ideally in one of { Rust, Java/Kotlin, Swift, Go, Ruby }
• Strong bitcoin/cryptographic fundamentals (key generation, secure key management, transaction construction, signatures, multi-party computation)
• Experience advising product teams on how to address a broad set of security and privacy challenges
• Empathy for your customers and colleagues

• Interest in the opportunities and challenges that come with building a new product area from the ground up

Qualifications
You have:

• 10+ years of experience with the full lifecycle of critical production services (server or mobile). Ideally in one of { Rust, Java/Kotlin, Swift, Go, Ruby }
• Strong bitcoin/cryptographic fundamentals (key generation, secure key management, transaction construction, signatures, multi-party computation)
• Experience advising product teams on how to address a broad set of security and privacy challenges
• Empathy for your customers and colleagues

• Interest in the opportunities and challenges that come with building a new product area from the ground up