Software Engineer - Blockchain Payments Infrastructure

About the Role

We're hiring a Software Engineer - Blockchain Payments Infrastructure to join our innovative team at Halliday. As a Software Engineer, you'll play a crucial role in building the infrastructure that powers blockchain payments at scale. This is a unique opportunity to work with cutting-edge technology in a fast-paced environment.

What You'll Be Doing

• Build Payment Infrastructure: Architect and develop secure, scalable backend services that process blockchain payments, handle complex transaction flows, and integrate with payment rails (ACH, cards, crypto networks).
• Design Distributed Systems: Build robust APIs, services, and data pipelines that interact with multiple blockchain networks, ensuring high availability, security, and performance.
• Work with Blockchain Technology: Utilize and integrate open-source blockchain SDKs to interact with various networks (EVM chains, Solana, Bitcoin), protocols, and smart contracts.
• Ship Developer Tools: Contribute to Halliday's public SDKs and APIs, making it easy for developers to integrate blockchain payments into their applications.
• Drive Technical Excellence: Implement comprehensive testing frameworks, monitoring systems, and security best practices to ensure platform reliability and scalability.
• Collaborate Cross-Functionally: Work closely with product, frontend, design, and partnerships teams to deliver features that solve real problems and drive adoption.
• Innovate on Core Protocol: Expand and improve our cross-chain payment protocol, exploring new blockchain integrations, optimization strategies, and payment flows.

Requirements

• Strong Engineering Foundation: Experience building production backend systems, APIs, or distributed services. You write clean, maintainable code and understand system design fundamentals.
• Technical Depth: Experience with backend languages (TypeScript/Node.js, Go, Python, Rust) and building scalable services, databases, APIs, and cloud infrastructure.
• Systems Thinking: You understand how distributed systems work, including concepts like consistency, fault tolerance, data integrity, and security.
• Fast Learner: You're excited to dive into new technologies, whether that's blockchain protocols, cryptography, payment systems, or emerging infrastructure tools.
• Problem Solver: You break down complex problems systematically, make pragmatic technical decisions, and focus on delivering impactful solutions.
• Collaborative Spirit: You work well with cross-functional teams, communicate technical concepts clearly, and thrive in a fast-paced startup environment.

Nice to Have

• Blockchain Experience: Previous work with blockchain technologies such as EVM-based chains (Ethereum, Polygon, Base), Solana, or Bitcoin. Experience with Web3 libraries like ethers.js, viem, or web3.js.
• Payments Background: Experience building payment systems, processing financial transactions, or working with payment APIs (Stripe, Plaid, etc.). Understanding of payment rails, fraud detection, or compliance.
• Distributed Systems Experience: Work with message queues, event-driven architectures, microservices, or high-throughput data pipelines.
• Cryptography Knowledge: Understanding of cryptographic primitives, key management, signing mechanisms, or zero-knowledge proofs.
• Infrastructure Expertise: Experience with cloud platforms (AWS, GCP), containerization (Docker, Kubernetes), infrastructure as code (Terraform), or CI/CD pipelines.
• Smart Contract Development: Experience writing or auditing smart contracts in Solidity, Rust, or other blockchain languages.
• Open Source Contributions: Active participation in open source projects or maintenance of public libraries.

What We Offer

• Competitive compensation package, with unlimited PTO and a friendly work environment.
• For international candidates - we offer visa sponsorship!