Senior Software Engineer, Backend

Zip Co is a digital financial services company offering point-of-sale credit and digital payment services. The company is seeking a Senior Software Engineer to design, build, and operate scalable backend systems for card issuing, transaction processing, settlement, and other mission-critical payment workflows. The role also involves technical ownership, architectural contribution, cross-functional collaboration, mentoring, and responsible use of AI-assisted development.

Responsibilities:

• Build and evolve scalable card issuing, transaction processing and settlement systems that power critical Zip customer experiences
• Design reliable integrations across Stripe, banking partners and Zip’s internal platforms, ensuring transactions move securely and accurately at scale
• Own complex technical initiatives from design through production, making thoughtful tradeoffs across customer experience, reliability, security and delivery speed
• Contribute to the architecture of event-driven, distributed backend systems using .NET, C#, Azure, DDD and CQRS
• Build resilient payment systems that operate effectively within evolving regulatory, compliance and risk requirements
• Improve the reliability, observability and performance of production systems, identifying issues early and strengthening how Zip responds when they occur
• Partner with Product, Engineering and Infrastructure to navigate technical tradeoffs, de-risk unknowns and deliver solutions that support customer and business outcomes
• Raise engineering quality through thoughtful design and code reviews, automated testing, monitoring and strong development practices
• Leverage AI-assisted development throughout the software lifecycle to accelerate delivery, improve code quality and strengthen testing, debugging and technical problem-solving
• Explore practical applications of emerging AI capabilities to improve engineering workflows, automate repetitive work and help the team build more effectively
• Mentor and support engineers through pairing, code reviews, technical guidance and knowledge sharing

Requirements:

• Bachelor's degree in Computer Science, Software Engineering, or a related field, or equivalent practical experience
• 10+ years of software engineering experience designing, building, testing, and maintaining complex production systems
• Deep experience with .NET/C#, Azure Cloud Services, and distributed backend systems
• Experience designing systems using Domain-Driven Design (DDD), CQRS and event-driven architectures
• Experience building payment infrastructure, card issuing or transaction processing systems, including platforms such as Stripe Issuing, Marqeta or comparable in-house solutions
• Demonstrated ability to independently own complex technical initiatives from architecture and design through production delivery
• Strong understanding of reliability, observability, automated testing, system performance and production incident management
• Experience navigating the security, compliance, and operational considerations involved in building mission-critical financial systems
• Proven ability to influence technical decisions and partner effectively across Engineering, Product and other technical and business teams
• Experience mentoring engineers and strengthening engineering practices through code reviews, pairing and knowledge sharing
• Proven experience leveraging AI-assisted development tools across coding, testing, debugging and technical problem-solving to improve software quality, developer productivity and delivery speed
• Ability to evaluate and apply emerging AI capabilities to engineering workflows, using sound judgment to ensure quality, security and maintainability
• A high-ownership, collaborative approach aligned with Zip's values: Customer First, Own It, Stronger Together and Change the Game
• Remote-first opportunity for US-based employees with the option to work in-person out of our Manhattan office
• visa sponsorship is not available for this position
• A graduate degree is a plus