Zip is looking for a Senior Software Engineer to design and build scalable, resilient, and secure APIs and distributed systems to power merchant checkout and B2B payment flows in a high-traffic, cloud-native platform. The role aims to drive technical excellence and support key B2B payment and order flows, enabling merchants to initiate checkouts, get paid, and manage transactions.
Requirements
- Deep expertise with .NET / C, Azure Cloud Services, and building distributed systems in a modern backend environment
- Demonstrated ability to design systems using Domain-Driven Design (DDD), CQRS, and event-driven architectures
- Experience building B2B platforms or integrations, where external partners rely on stable, well-defined contracts - you understand the importance of backward compatibility, clear communication, and long-term reliability with partner-facing integrations
- Strong understanding of authentication and security fundamentals, including key management and securing B2B integrations
- Hands-on experience with financial or transactional systems - you understand concepts like order lifecycle, refunds, invoicing, and reconciliation, and have worked on systems where correctness and traceability are critical
- Proven experience leveraging AI-based tooling (e.g., GitHub Copilot, CodeWhisperer, ChatGPT, or similar) to enhance code quality, productivity, and problem-solving workflows
- An architecture mindset, with the ability to design and evolve APIs and services that support flexibility, scalability, and clear separation of concerns
Responsibilities
- Design and build scalable APIs for merchant integrations (checkout initiation, pre-qualifications, order confirmation, capture and refunds)
- Support customer checkout flows, including complex scenarios like pre-orders, backorders, and add-ons (insurance, warranty)
- Support flexible merchant configuration - enabling internal teams (e.g. account managers, integration managers) to control which features and flows are enabled per merchant
- Own architectural decisions that support an event-driven, domain-oriented backend using .NET, C, and Azure Cloud Services
- Implement distributed systems using DDD and CQRS
- Integrate with third-party accounting systems to support financial operations and reconciliation
- Collaborate with security to implement robust authentication patterns, tokenization strategies, and secure key management practices (e.g. key rotation)
Other
- 10+ years of hands-on software engineering experience, including senior-level architecture and delivery ownership
- Comfort working cross-functionally with product managers, compliance, security, and account/integration managers to align on real-world business needs
- Experience mentoring others and improving team-wide engineering practices
- Familiarity with observability tools, system performance optimization, and production incident management
- Remote-first opportunity for US-based employees with the option to work in-person out of our Manhattan office
