Senior C++ Software Engineer - Mobile Payment SDK (Qt, Security, EMV)

G+D Netcetera builds secure digital payment solutions for banks, card issuers and wallet providers across Europe. It is part of the Giesecke+Devrient security technology group. In our Payment Security division, the Trusted Payments team helps issuers bring their cards into every digital channel. One example is a tap-to-pay wallet inside the bank’s own mobile app, an alternative to Apple Pay and Google Pay.

Convego CloudPay uses Host Card Emulation (HCE) so that a smartphone can act as a contactless payment card without special hardware. At its core is our client library: a cross-platform C++/Qt engine embedded in banking apps on Android and iOS. It handles the card schemes’ payment logic, token storage and cryptography. Millions of payments depend on it working correctly, securely and in line with EMVCo and scheme requirements.

• Own the CloudPay client library (C++/Qt) end to end: maintenance, bug fixing, security updates and technical specification.
• Troubleshoot and support our bank customers, working with product owners, QA and the mobile and backend teams.
• Produce and release customer-specific builds for Android and iOS: configurations, certificate renewals, and platform updates for new OS versions.
• Maintain and update third-party dependencies such as Qt, OpenSSL and the security/obfuscation toolchains, and cross-compile them for different targets.
• Keep the CMake and Jenkins CI build pipeline healthy, and automate with Python.
• Help our customers move to our next-generation SDK (CloudPay Nova).
• Maintain the Node.js sandbox/simulator that customers use for integration testing.
• Take part in certification and security reviews: delta documentation, scheme requirements, pentest findings.

• Solid professional experience in modern C++, ideally with Qt.
• CMake and cross-platform builds, including cross-compiling third-party libraries.
• Python for tooling and automation.
• CI/CD, preferably Jenkins.
• A careful, quality-focused working style. You enjoy owning a mature, business-critical product and talking directly to customers’ engineers.
• Fluent English.

• Android (NDK, AAR) and/or iOS (Xcode, frameworks) build and integration experience.
• Applied cryptography, OpenSSL, TLS/PKI, mobile app hardening (obfuscation, white-box crypto, root/jailbreak detection).
• EMV and contactless payments, tokenization (MDES/VTS), card scheme certification.
• Node.js.