Engineering Lead Crypto and DeFi

We’re hiring a Tech Lead to own our DeFi and onchain product stack end-to-end. You’ll lead the architecture and development of systems that power our asset management, lending/borrowing, and earn products.

This role is highly hands-on. You’ll design and build backend services, blockchain integrations, and transaction infrastructure while ensuring secure interaction with smart contracts, wallets, and custody systems.

You’ll also help grow the engineering team as we scale — setting technical direction, mentoring engineers, and establishing strong engineering practices.

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• Own the DeFi architecture across backend services, blockchain integrations, and supporting systems.
• Build and integrate DeFi products including lending, borrowing, yield, and liquidity strategies.
• Design secure blockchain interactions, including wallet infrastructure, signing flows, and custody integrations (MPC, multisig, hardware wallets).
• Develop backend systems for transaction management, protocol integrations, and onchain/offchain coordination.
• Lead engineering execution — define architecture, review code, and ensure systems remain reliable, scalable, and secure.
• Hire and mentor engineers as the team grows, establishing strong technical standards.
• Collaborate closely with product and design to deliver high-quality user-facing financial products.

• 8+ years of software engineering experience, with experience leading technical projects or teams.
• Strong backend engineering experience in one or more of the following:
  Go, Python, or Node.js.
• Experience building production systems that integrate with blockchain networks.
• Familiarity with Solana and/or EVM-compatible chains.
• Strong understanding of DeFi systems, including lending/borrowing protocols, swaps, liquidity aggregation, and yield strategies.
• Knowledge of DeFi risk mechanics such as collateral management, liquidations, staking, and yield generation.
• Experience designing APIs, distributed services, and database-backed systems.
• Experience building or operating cloud-based systems (AWS or similar).
• Strong communication skills and ability to drive engineering execution in a fast-moving environment.

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Nice to have:

• Experience with smart contract development (Solidity, Rust, or similar).
• Experience integrating with custodial and non-custodial wallet solutions.
• Exposure to cross-chain infrastructure or multi-chain architectures.
• Experience with frontend technologies such as React or Next.js.
• Experience scaling engineering teams in a high-growth startup environment.
• Familiarity with AI-assisted development tools (Copilot, Cursor, agentic workflows).

Please send your resume to careers@kastcard.com

At this time, we receive a lot of applications, so please bear with us to hear back from us.