Senior Software Engineer (Card Present)
Century Business Solutions6 months ago
Irvine, CA, USASenior
Responsibilities
- Design, develop, and maintain backend services managing communication between payment terminals and processing infrastructure.
- Integrate Clover, Stripe Terminal, Square, and similar card-present providers and adapt their APIs to the platform architecture.
- Build device hub capabilities for terminal provisioning, configuration management, firmware coordination, and health monitoring.
- Own EMV Level 3 certification efforts, including test planning, certification tooling, and resolution of findings.
- Design card-present infrastructure for international markets, regional EMV differences, multi-currency support, and varying acquiring-market certification requirements.
- Build scalable backend services using .NET and C# and contribute to architectural evolution.
- Implement retry logic, timeout handling, and graceful degradation for network instability and device failures.
- Write secure code meeting PCI DSS requirements, including cardholder data handling, encryption, and key management.
- Apply P2PE and tokenization standards within device integration and transaction-processing layers.
- Mentor junior and mid-level engineers through pair programming, code reviews, and knowledge sharing.
- Document card-present domain knowledge, certification processes, integration quirks, and device-specific behaviors.
Requirements
- Strong proficiency in C# and the .NET ecosystem, with experience building production-grade backend services and APIs.
- Hands-on experience with EMV chip, contactless/NFC, and magnetic-stripe payment flows, ideally including EMV Level 3 certification.
- Experience integrating payment terminal hardware and device-management platforms, including terminal communication protocols such as TLV or ISO 8583.
- Understanding of PCI DSS requirements for card-present environments, including encryption, key injection, and secure cardholder-data handling.
- Experience designing and building reliable, clearly versioned RESTful APIs.
- Experience building low-latency, high-reliability backend services in payments or a similarly demanding production environment.
- Direct experience with Clover, Stripe Terminal, Square, or similar card-present platforms and developer SDKs.
- Familiarity with EMV kernel development or customization, regional EMV certification requirements, and acquiring-bank differences across international markets.
- Experience with Ingenico, Verifone, PAX, or other payment-terminal hardware vendors.
- Experience with network tokenization or scheme-token management in a card-present context.
Benefits
- Full-time employment.
- The company describes learning opportunities, career growth potential, and a dynamic work environment.
Tech Stack
C#.NET
Categories
About Century Business Solutions
Century Business Solutions builds EBizCharge, an integrated payments platform and gateway for businesses using ERP, accounting, and eCommerce systems. It provides embedded payment modules and connectors for QuickBooks, Sage, Microsoft Dynamics, NetSuite, SAP Business One, Acumatica, Epicor, Magento, and WooCommerce, plus hosted and mobile options. Privately held and founded in 2004, the company is headquartered in Irvine, California and generates revenue through payment processing and related software services.