Principal .NET Software Engineer - Cloud Payments Platform

About the role

Versapay is a payments technology company that helps businesses manage their accounts receivable efficiently. We aim to streamline processes, unlock working capital, and accelerate business growth. Our platform processes over 110 million transactions and $257 billion annually, serving over 10,000 customers.

Responsibilities

• Own and evolve core payment services for online (CNP), device-based EMV (CP), digital wallets (e.g., Apple Pay, Google Pay), and payment facilitator/orchestration flows.
• Modernize and improve existing components into more cloud-native, distributed architectures using containers on AWS/Azure.
• Own and extend end-to-end payment workflows: authorization, capture, void, refund, tokenization, clearing, funding, settlement, and multi-source reconciliation.
• Expand capabilities for international payments, including multi-currency and cross-border flows.
• Integrate with payment service providers (PSPs), EMV card readers, and device SDKs using secure, standards-based messaging.
• Improve and maintain CI/CD pipelines in GitHub Actions (automated builds, tests, security scans, packaging, deployments).
• Design and evolve test automation strategy, covering domain-level logic, API contracts, and integration with external processors and devices.
• Strengthen platform reliability through observability (metrics, logs, traces), fault-tolerant design, and automated operational workflows.
• Partner with Product, Security, Compliance, and Operations to deliver features that balance customer experience, regulatory requirements, risk, and operational robustness.
• Mentor engineers, lead design and architecture discussions, and influence the long-term strategy for the payments platform.

Requirements

• Significant experience (typically 10+ years) of professional engineering with expert proficiency in C#, .NET, and SQL.
• Deep experience in payments: online payments, EMV device-based transactions, digital wallets (e.g., Apple Pay, Google Pay), PayFac/orchestration flows, bank account rails (ACH/EFT), and international/multi-currency payment flows.
• Proven ability to modernize production financial systems into cloud-native, distributed architectures.
• Familiarity with monitoring and observing distributed systems using modern observability tooling.
• Proven ability to work cross-functionally with Product, Security, Compliance, and Operations, and to represent engineering effectively to non-technical stakeholders.
• Experience using AI-assisted development tools to enhance productivity and code quality.
• Deep hands-on experience with several of the following: ISO 8583 transaction messaging, ISO 20022 data models and payment messaging, DUKPT key-management and secure device cryptography, Hardware Security Modules (HSMs) and secure key lifecycle, EMV payment kernels and card/device authentication flows.
• Strong knowledge of modern API and integration design (RESTful services), asynchronous messaging/queueing, caching, event-driven architecture, high-availability patterns, AWS or Azure, containerization, orchestration, and CI/CD automation, PCI-DSS, encryption, tokenization, key-rotation, and secure coding principles.

Qualifications

• Experience with multi-region cloud architecture and distributed data patterns.
• Experience with modern UX/front-end development (e.g., JavaScript/TypeScript).

Benefits

• We are an equal opportunity employer and value diversity at our company.
• We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.
• We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses and identifying potential inconsistencies or verification signals in application materials based on available information.
• Final hiring decisions are ultimately made by humans.
• If you would like more information about how your data is processed, please contact us.