Blockstream is the leading Bitcoin company, providing cutting-edge infrastructure solutions for enterprises, institutions, and individual Bitcoin users. We develop industry-leading Bitcoin self-custody solutions, Bitcoin-based financial products, second-layer scaling technologies, and enterprise-grade blockchain infrastructure. Simplicity is our next-generation, functional, low-level programming language for blockchain applications, designed for provable security and formal verification. SimplicityHL is the high-level layer built on top of it, intended to make Simplicity more accessible for real-world application developers. We’re looking for a Programming Language Developer to focus on non-core language design areas for SimplicityHL — building the developer experience, tooling, and infrastructure that make the language productive and maintainable at scale. You’ll work alongside the Simplicity language researchers developing the developer-focused aspects of the language that turn SimplicityHL into a complete, usable platform. This means designing and implementing unit testing frameworks, module/package systems, versioning and upgrade paths, documentation tooling, build pipelines, and other ecosystem infrastructure. Your work will directly impact every developer building with SimplicityHL, making it easier to test, organize, share, and evolve their smart contracts.