Lead API Developer - Payment Systems

API Developer - Payment Systems Location: Toronto, ON (Hybrid - Onsite 2 Days per Week) Duration: 6-12 Month Contract Potential: Contract-to-Hire Opportunity Position Overview We are seeking a highly experienced Lead API Developer - Payment Systems to provide technical leadership for the development, integration, security, and modernization of enterprise payment APIs. This role is focused on leading code reviews, driving technical decisions, mentoring developers, and ensuring the successful delivery of secure and scalable payment solutions. The ideal candidate will bring strong AWS expertise, deep knowledge of payment processing systems, and the ability to communicate complex technical concepts to both technical and business stakeholders. Experience within banking, financial services, FinTech, or payment processing environments is highly desirable. Key Responsibilities Lead code reviews and technical design discussions for payment API development initiatives.Drive architecture and implementation decisions to ensure scalability, performance, maintainability, and security.Establish coding standards, best practices, and development guidelines across engineering teams.Mentor junior developers and provide technical leadership throughout the software development lifecycle.Collaborate with business stakeholders and senior leadership to communicate technical constraints, trade-offs, and solution recommendations.Oversee the integration of payment APIs with external payment networks and financial systems.Own the quality, reliability, and security of payment API implementations.Ensure compliance with security, privacy, and regulatory requirements related to payment processing.Support payment platform modernization and cloud migration initiatives.Implement and promote secure development practices including encryption, tokenization, authentication, authorization, and PII protection.Required Qualifications 5+ years of experience in software development, API development, or technical leadership roles.Strong AWS experience supporting cloud-based application development and integrations.Proven experience leading code reviews and making technical design decisions.Strong understanding of API design, integration patterns, and distributed systems.Experience working with payment processing systems, payment APIs, or financial transaction platforms.Strong knowledge of software security principles, including encryption, tokenization, and sensitive data handling.Ability to communicate technical concepts effectively to business and executive stakeholders.Strong troubleshooting, analytical, and problem-solving skills.Experience mentoring developers and promoting software engineering best practices.Preferred Qualifications Experience with payment rails such as:ACHSWIFTWire TransfersEFTE-TransferBanking, financial services, payment processor, or FinTech industry experience.Experience with payment gateways, settlement systems, and reconciliation processes.Knowledge of PCI-DSS requirements and payment security standards.Experience developing and supporting high-volume transaction processing platforms.Familiarity with cloud migration and modernization programs.