Crossbar

Compensation

Full Description

About the Role: We are looking for an experienced blockchain engineer to lead the design and development of our Wallet SDK, which powers mobile, browser, desktop, and embedded applications. This SDK acts as a high-level wrapper that integrates cryptographic primitives, our MPC SDK, and backend services into a unified developer experience. Your mission is to deliver a full-featured, ready-to-use SDK that enables end-user platforms to interact seamlessly with multiple blockchains — without needing to manage low-level cryptography or protocol quirks. As a senior technical leader, you will architect modular blockchain support within the SDK, ensuring that developers can directly build wallet features such as transfers, staking, swaps, and governance across chains with minimal effort. Key Responsibilities: • SDK Architecture & Development: • Design, implement, and maintain a cross-platform Wallet SDK built on Kotlin Multiplatform (KMP), with seamless integration for native Swift (iOS) and native Android platforms. • Full Blockchain Support: • Implement end-to-end blockchain functionality inside the SDK (transaction construction, broadcasting, staking, governance, DeFi features). Consumers should be able to “just call the SDK” to perform blockchain actions. • Integration of Core Components: • Orchestrate cryptographic primitives, the MPC SDK, and backend services into a single, easy-to-consume package — hiding complexity from end-user apps. • API & Interface Design: • Define clear, developer-friendly APIs that abstract blockchain complexity and provide a consistent interface across mobile, browser, desktop, and embedded platforms. • Performance & Reliability: • Ensure the SDK is lightweight, high-performance, and stable across different environments, with robust error handling and network resilience. • Testing & Documentation: • Build automated test coverage (unit, integration, multi-chain scenarios). Maintain excellent in-code documentation and collaborate with DevRel/product teams to provide developer guides. • Collaboration & Mentorship: • Work with backend, infra, and product engineers to align on roadmap delivery. Mentor junior engineers and guide SDK development best practices. Requirements: • Bachelor’s or Master’s degree in Computer Science, Software Engineering, or equivalent experience. • 5–10 years of professional software engineering, with at least 3+ years in blockchain, SDK, or wallet-related development. • Strong coding skills in Kotlin Multiplatform, plus experience with native Swift (iOS) and native Android. • Proven experience delivering multi-chain SDKs or integrations (EVM, Cosmos, Aptos, Sui, Tezos, Solana, etc.), with support for key wallet features. • Demonstrated ability to design developer-friendly APIs that abstract protocol complexity. • Experience with CI/CD pipelines, SDK packaging/distribution, and versioning. • Strong collaboration skills across engineering, product, and infra teams. • Optional: Open-source contributions in blockchain SDKs/wallets, or prior leadership in multi-chain wallet projects.