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Senior Firmware Developer — Smartcard & Mobile Credentials (m/f/d)

SimonsVoss Technologies GmbH

Unterföhring
70,000 - 95,000 €

11.5.2026

As a Senior Firmware Developer, you will design and implement C++ application firmware on microcontrollers (ARM Cortex-M) running an RTOS. Your focus will be on application-level features and the integration of physical and smartphone-based credential processing flows (Mifare DESFire, HCE, mobile wallets).

Tasks

Implement C++ application-layer firmware on an RTOS (tasking, IPC, power-aware scheduling).
Develop application logic for existing (Mifare DESFire) and future standards: app/file model, access conditions, personalization, and lifecycle management.
Integrate NFC/BLE/WLAN stacks and mobile credential workflows (provisioning, HCE, revocation).
Interface with secure elements / SAMs for key storage and transaction offload. Implement secure boot, signed/encrypted OTA, and application-level runtime protections.
Enhance and maintain internal software suites (C++, C#).
Build tests and CI/CD artifacts; use protocol sniffers and hardware debuggers for validation.
Work closely with mobile, backend, hardware, and QA teams; produce technical and security documentation.

Requirements

+5 years of embedded firmware experience.
Strong C++ experience for microcontrollers in resource-constrained environments and practical RTOS experience (Zephyr is an advantage).
Hands-on RFID / NFC experience (ISO 14443, Mifare DESFire EVx preferred).
Experience with smartphone credential flows (mobile wallets, HCE, provisioning).
Familiarity with applied cryptography in embedded systems (secure messaging, AES/HMAC, key usage), secure elements / SAM integration, secure boot, and OTA.
Debugging skills (JTAG/SWD, logic analyser) and embedded CI/CD experience.
Nice to have: Deep Mifare DESFire EVx personalization experience, low-power design, mobile platform SDKs/APIs, knowledge of access control standards, security compliance (CRA, NIST, ETSI), and familiarity with Git, Jira, and embedded test frameworks.

Team

We have a bright team from 17 nations, with great helpfulness & cohesion.

Application Process

First Introductory Video-Interview with HR💻
Video-Interview with Managers and HR 💻
Meet the Team 🏢

Relevant Skills

ZephyrBluetooth LowenergyDebuggingC++Embedded Systems

Required Languages

German (Conversational)English (Fluent)

Benefits

30+ vacation days

30 Tage Urlaub ohne Sperrfrist in der Probezeit

Professional Development

Individuelle Weiterbildung- & Beratungsangebote, praxisnahe Schulungen, Zugang zu Sprachkursen, Allegion Academy & LinkedIn Learning

Job bicycle

kostengünstiges Leasing von Jobrad und E-Bikes

Pension Plan

Firmenrenten-Zuschuss (40 € plus 20 % des Umwandlungsbetrags)

Daycare

Bis zu 250 € brutto Kinderbetreuungszuschuss pro Monat

Health Program

30€ brutto Fitnesszuschuss im Monat

Free beverages

freie Getränke & frisches Obst

Flexible Working Hours

Permanent contract

Accessibility

Language courses