Principal .NET Software Engineer- Cloud Payments Platform

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