We are expanding our
Card Present platform, the infrastructure that powers
in-person, tap, dip, and swipe transactions at point-of-sale, and are looking for a Senior Engineer who combines deep payments domain expertise with strong backend engineering fundamentals.
Responsibilities- Design, develop, and maintain backend services that manage communication between payment terminals and our processing infrastructure, supporting EMV chip, NFC/contactless, and magnetic stripe transaction flows.
- Integrate with device management platforms and terminal SDKs including solutions such as Clover, Stripe Terminal, Square, and similar off-the-shelf card present providers, adapting their APIs to fit our platform architecture.
- Implement and maintain device hub capabilities including terminal provisioning, configuration management, firmware coordination, and health monitoring.
- Own and drive EMV Level 3 certification efforts in partnership with payment networks and device vendors, coordinating test plans, managing certification tooling, and resolving certification findings.
- Design and build card-present infrastructure with international markets in mind, accounting for regional EMV implementation differences, multi-currency support, and varying certification requirements across acquiring markets.
- Build scalable, maintainable backend services using .NET and C#, adhering to established architectural patterns and contributing to their evolution.
- Implement robust retry logic, timeout handling, and graceful degradation to ensure transaction integrity even in the presence of network instability or device failures.
- Write secure code that meets PCI DSS requirements across all card-present transaction flows, with a particular focus on cardholder data handling, encryption, and key management.
- Apply point-to-point encryption (P2PE) and tokenization standards correctly within device integration and transaction processing layers.
- Act as a technical resource and mentor for junior and mid-level engineers on the squad, supporting their growth through pair programming, code review feedback, and knowledge sharing.
- Document card-present domain knowledge including certification processes, integration quirks, device-specific behaviors
Qualifications- Strong proficiency in C# and the .NET ecosystem, with experience building production-grade backend services and APIs.
- Hands-on experience with EMV payment flows including chip, contactless/NFC, and magnetic stripe, ideally including direct involvement in EMV Level 3 certification processes.
- Experience integrating with payment terminal hardware and device management platforms, with an understanding of terminal communication protocols (TLV, ISO 8583, or similar).
- Solid understanding of PCI DSS requirements as they apply to card-present environments, including encryption, key injection, and secure cardholder data handling.
- Experience designing and building RESTful APIs with a focus on clarity, versioning, and reliability.
- Proven ability to build low-latency, high-reliability backend services in a payments or similarly demanding production environment.
- Direct experience with Clover, Stripe Terminal, Square, or similar off-the-shelf card present platforms and their developer SDKs.
- Familiarity with EMV kernel development/ customization, regional EMV certification requirements and acquiring bank differences across international markets.
- Background working with Ingenico, Verifone, PAX, or other terminal hardware vendors.
- Experience with network tokenization or scheme token management in a card-present context.
Job Type: Full-time
