Senior Software Engineer Payments Treasury

Who We Are: Alpaca is a US California headquartered brokerage infrastructure technology company and self-clearing broker-dealer, delivering execution and custody solutions for Stocks, ETFs, Options, Cryptocurrencies, and more, and has raised over $170 million in funding. Amongst our subsidiaries, Alpaca is a licensed financial services company in multiple countries, and we serve hundreds of financial institutions globally such as broker-dealers, investment advisors, hedge funds, and crypto exchanges. Alpaca’s globally distributed team members bring in diverse experiences such as engineers, traders, and brokerage professionals to achieve our Mission of opening financial services to everyone on the planet. We are also deeply committed to open-source contributions and fostering a vibrant community. We will continue to enhance and improve our award-winning developer-friendly API and the infrastructure behind it. Our Team Members: We’re a team of 150+ globally distributed members who love working from our favorite places worldwide. Our team spans the USA, Canada, Japan, Hungary, Nigeria, Brazil, the United Kingdom, and more! We’re looking for candidates eager to join Alpaca’s growing organization, who are excited about our Mission of “Open financial services to everyone on the planet and share our Values of “Stay Curious,” “Have Empathy,” and “Be Accountable.”   Your Role As a Senior Backend Software Engineer on our Payments team, you will architect, build, and scale mission-critical financial systems that form the foundation of Alpaca's global treasury platform. You'll be responsible for systems that process billions of dollars in transactions daily while ensuring financial integrity, regulatory compliance, and operational excellence. Key Responsibilities: Design and implement robust, scalable payment processing systems that support ACH and SWIFT payment rails, with architecture capable of expanding to additional payment networks across multiple jurisdictions Architected and maintained financial ledger systems that enforced proper accounting principles,s including double-entry bookkeeping, balance sheet integrity, and transaction immutability Develop two-phase transfer mechanisms that ensure atomicity, consistency, isolation, and durability (ACID) in financial transactions Create automated reconciliation systems for transaction verification, account balancing, and error detection Implement financial controls,s including segregation of duties, approvals workflow, and audit trails Build and enhance settlement systems that maintain perfect financial record-keeping with complete audit history Design and implement secure, auditable APIs for internal and external payment services Contribute to technical decision-making for the payments infrastructure roadmap Mentor junior engineers and participate in code reviews to maintain high engineering standards Technical Environment: Backend services primarily written in Go with a microservices architecture API services using gRPC for internal communication and RESTful interfaces for external systems Event-driven design patterns using message brokers for asynchronous processing PostgreSQL for transactional data with strong consistency requirements Kubernetes for containerization and orchestration on Google Cloud Platform Rigorous testing practices, including unit, integration, and end-to-end tests Continuous integration and deployment pipelines Must-Haves: 5+ years of backend engineering experience with at least 3 years working with distributed systems at scale Strong expertise in Go, including production experience building and maintaining Go microservices Deep understanding of financial transactions, payment processing systems, and transaction safety Experience with ACH and SWIFT payment networks and their technical requirements Strong knowledge of financial accounting principles including: Double-entry accounting with debits and credits Trial balance reconciliation General ledger man...