Software Engineer

Halliday is a blockchain company and product lab working to create a unified, cross-chain payments ecosystem. Its flagship product, Halliday Payments, is a unified payments platform that makes it easy for users to onramp, swap, and take other onchain actions. Halliday’s products are built on the Workflow Protocol, which removes the need to code smart contracts by hand and enables breakthrough applications to ship in hours, not years.

Backed by a16z and #Hashed, Halliday has worked with prominent developers such as ApeChain, Story Protocol and DeFi Kingdoms to provide seamless experiences for both developers and users. The team includes alumni from Stanford, Harvard, Compound, Meta, Netflix, and more.

As a Software Engineer at Halliday, you'll build the infrastructure and services that power blockchain payments at scale. You'll design and implement secure, distributed systems that handle millions of transactions across multiple chains, working on challenging technical problems at the intersection of payments, blockchain, and cryptography. This is an opportunity to work on cutting-edge technology with a talented team that's making blockchain accessible and practical for everyday commerce.

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.

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.

Location: Based in or willing to relocate to the San Francisco Bay Area or New York City.

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.

A role with significant autonomy to build out the next generation infrastructure of the blockchain space.

Competitive compensation package, with unlimited PTO and a friendly work environment.

For international candidates - we offer visa sponsorship!

The base salary range for this role is $150,000 - $190,000. This reflects the minimum and maximum range across all US locations. This does not include equity or benefits.

The actual base pay is dependent upon many factors, such as: experience, relevant skills, and role level. Your recruiter can share more about the compensation and benefits applicable to your location during the hiring process.