ENVIRONMENT: A rapidly growing US-based FinTech company seeks the coding talents of a Backend Developer who will architect and build the clients“ new payment platform and financial ledger system from the ground up. In this role, you“ll be the technical cornerstone of clients next-generation payment infrastructure, designing and implementing a robust double-entry bookkeeping system with event-driven architecture. With strong expertise in distributed systems and financial technology, you“ll design and implement a scalable, fault-tolerant payment platform that handles complex financial transactions with absolute reliability and consistency. You“ll build mission-critical systems that process financial data with the highest standards of accuracy, security, and auditability. The ideal candidate must have 6 years of Backend Software Development experience, with at least 3 years building financial systems, payment platforms, or ledger services. DUTIES: Implement Financial Ledger Build a double-entry bookkeeping system that maintains strict data integrity and audit trails for all financial transactions. Build Event-Driven Architecture Develop an event-first architecture using Kafka to ensure reliable, scalable message processing for financial transactions. Orchestrate Complex Workflows Implement robust workflow orchestration using Temporal.io to manage multi-step payment processes, reversals, and reconciliation tasks. Product Mindset Passionate about creating value for users, with a focus on outcomes rather than just output. Ensure Financial Accuracy Create systems that guarantee accurate accounting, prevent race conditions, and maintain strict consistency in financial records. Develop Integration Layer Design and build APIs that securely connect our platform with banking partners, payment processors, and other financial institutions. Implement Compliance Features Build functionality that ensures regulatory compliance, including transaction monitoring, reporting, and audit capabilities. Establish Resilient Systems Design for fault-tolerance with emphasis on recovery mechanisms, transaction replay capability, and comprehensive audit logs. Collaborate on Architecture – Work closely with the engineering leadership to define architectural patterns and infrastructure choices that enable scale and reliability. Documentation and Knowledge-Sharing – Create comprehensive documentation of system design, financial models, and technical decisions. Mentor team members on financial systems best practices. REQUIREMENTS: 6 Years of Backend Software Development experience, with at least 3 years building financial systems, payment platforms, or ledger services. Deep understanding of financial ledgers, double-entry bookkeeping principles, and reconciliation processes. Experience with financial data modelling and transaction flow design. Strong experience with event sourcing, CQRS patterns, and message broker systems, particularly Kafka for high-throughput financial systems. Experience making informed technical decisions that balance user needs, business goals, and engineering constraints. Experience with workflow orchestration frameworks, ideally Temporal.io, for managing complex, long-running financial processes. Proven track record building highly available, fault-tolerant distributed systems with an emphasis on data consistency and reliability. Expert-level understanding of database transaction models, consistency patterns, and optimizations for financial data. Ability to architect complex systems with careful consideration for scalability, maintainability, and operational excellence. Strong knowledge of security best practices for financial applications and data protection. Ability to work remotely with your own equipment. Willingness to overlap work hours until 12:00-13:00 EST (negotiable). Tech Stack Core Technologies: Kafka, Temporal.io, PostgreSQL Languages: Ruby Infrastructure: AWS, Pulumi Observability: PagerDuty, Sentry Development Tools: GitHub, Docker Bonus FinTech Experience: Previous work in cross-border payments, banking platforms, or currency exchange systems. Regulatory Knowledge: Familiarity with financial regulations, compliance requirements, and security standards for payment systems. Cloud Infrastructure: Experience with cloud-native services, infrastructure as code, and containerization for financial applications. Performance Optimization: Track record optimizing high-volume transaction systems for throughput and latency. International Payment Systems: Understanding of SWIFT, SEPA, Fedwire, or other international payment networks. ATTRIBUTES: Proven ability to make sound technical decisions, mentor other engineers, and communicate complex concepts clearly. Exceptional analytical abilities to solve complex financial and technical challenges. While we would really like to respond to every application, should you not be contacted for this position within 10 working days please consider your application unsuccessful. COMMENTS: When applying for jobs, ensure that you have the minimum job requirements. Only