Spiral Blockchain Engineer

Spiral (formerly Square Crypto) builds and funds free, open-source projects that advance the use of bitcoin as a tool for economic empowerment. The core team is mainly focused on contributing to the Lightning Development Kit (LDK), a tool that simplifies how developers add the Lightning Network – fast, cheap, global bitcoin payments – to applications. In addition, Spiral’s wildly successful grant program supplies funding to dozens of FOSS (free and open-source) bitcoin developers, designers, PMs, and educators all around the world.

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We’re looking to grow the six-person engineering team that exclusively works on developing the Lightning Development Kit (LDK).

LDK is a comprehensive open-source project that lets developers efficiently build Lightning applications. It includes a full implementation of the Lightning Network protocol written in Rust, APIs, language bindings, demo apps, and more. LDK is used by dozens of projects worldwide, including Lightspark, Cash App, Alby, and Bit Kit.

The LDK engineers who work for Spiral spend significant time writing code, reviewing code, answering questions, writing documentation, and accepting sensible patches and pull requests from other contributors. LDK aims to build a sustainable open-source project that is welcoming to newcomers, beneficial to users, and ultimately not reliant on a single funding source. The development roadmap is transparent, and corporate priorities do not come first;

users do.

• Contribute to LDK by writing and reviewing code, improving testing infrastructure, and assisting projects and companies that use LDK
• Help add and maintain features such as the following:
  • Language bindings, including Java/Kotlin, C#, JavaScript/WASM/browser extensions, and Swift
  • Support for splicing and dual-funded channels
  • Support for Taproot, including musig, PTLCs, multi-sig scripts, and custom scripts
  • Improve the performance, scalability, and robustness of LDK
  • BOLT 12, VSS, and anchor outputs
  • A server version of LDK
• When you’re not doing all of that, you’ll improve bitcoin through passion projects of your choosing. Almost anything goes.

• 8+ years of professional experience
• Hands-on experience with bitcoin and the Lightning Network
• Experience programming with Rust, C, or C++
• Ability to thrive in ambiguity and build creative solutions to complex problems
• Appreciation for bitcoin

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