[Hiring] Senior Zephyr RTOS / Embedded Systems Engineer @L4B Software

Role Description

This is a hands-on Zephyr RTOS platform-engineering role. We need an engineer who can work inside and around Zephyr itself — close to the MCU, BSP, drivers, interrupts, memory, timing, boot flow, and hardware. If your experience is primarily developing applications on top of an RTOS without hands-on experience with Zephyr internals, BSP/board bring-up, DeviceTree/Kconfig, device drivers, MCU architecture, or low-level hardware/software debugging, this role will not be the right match.

We are looking for a Senior Zephyr RTOS / Embedded Systems Engineer to help build and evolve MediTUX-RT, L4B's real-time operating-system platform for embedded and medical-device applications. This is a Senior Individual Contributor role requiring substantial technical ownership. You will work directly with:

• Zephyr, MCU platforms, BSPs, drivers, interrupts, memory, timing, boot processes, firmware, and hardware integration
• Collaborating with embedded, Linux, cybersecurity, validation, and quality engineers

What You'll Do:

• Develop, integrate, and maintain Zephyr RTOS-based embedded platforms.
• Work directly with Zephyr internals, kernel configuration, Kconfig, DeviceTree, west, and the Zephyr build system.
• Perform board bring-up and BSP development/integration for MCU-based hardware.
• Develop, integrate, and debug device drivers and hardware interfaces.
• Work with peripherals and buses including SPI, I2C, UART, CAN, GPIO, timers, ADC, PWM, and watchdogs.
• Debug issues involving interrupts, concurrency, synchronization, scheduling, memory, timing, and hardware interaction.
• Analyze and improve real-time behavior, determinism, latency, resource usage, and system reliability.
• Work with bootloaders, firmware updates, flash layouts, and device startup flows.
• Develop production-quality embedded C/C++.
• Investigate complex problems using JTAG/SWD, GDB, logic analyzers, oscilloscopes, and hardware debugging tools.
• Develop automated tests and platform-level validation.
• Contribute to secure firmware design, including Secure Boot and secure update mechanisms where applicable.
• Produce maintainable technical documentation and engineering evidence suitable for long-lifecycle and regulated products.
• Collaborate with hardware, validation, cybersecurity, quality, and other platform-engineering teams.

Qualifications

• Strong professional experience in embedded systems and firmware development.
• Significant hands-on experience with Zephyr RTOS.
• Strong understanding of RTOS concepts including scheduling, threads, interrupts, synchronization/IPC, timers, memory management, concurrency, and real-time constraints.
• Strong embedded C development skills; C++ experience is valuable.
• Hands-on experience with MCU-based systems, ideally ARM Cortex-M.
• Experience with board bring-up, BSPs, and low-level hardware integration.
• Experience developing or debugging device drivers.
• Practical experience with Zephyr DeviceTree and Kconfig.
• Strong hardware/software debugging skills.
• Ability to investigate problems across the complete stack — from software behavior through RTOS and drivers down to the hardware.
• Ability to independently own and resolve complex platform-level technical problems.

Requirements

• Experience in several of the following areas would be particularly valuable: Zephyr Upstream Development, Custom Zephyr Boards/SoCs/Drivers, ARM Cortex-M, Nordic, NXP, STM32, Renesas, Infineon, MCUboot, Secure Boot, Secure Firmware Updates, ARM TrustZone-M, Embedded Cryptography, BLE, CAN/CAN-FD, USB, Networking, Flash Storage, Power Management, HIL Testing, Python Automation, CI/CD.
• Experience with medical-device, safety-critical, security-sensitive, or other regulated embedded products is a strong advantage, including exposure to IEC 62304, ISO 14971, IEC 61508, or comparable development environments.

What This Role Is Not

• This is not primarily: Embedded application development on top of an RTOS.
• Embedded Linux engineering.
• Android/AOSP engineering.
• Hardware design.
• Project management.
• People management.

What Success Looks Like

• You become a technical owner of significant parts of MediTUX-RT.
• You can take a new MCU or board, understand what is required to support it, bring the platform up, integrate and debug the necessary components, and drive technical issues through to resolution.
• When timing, memory, driver, interrupt, boot, or hardware-related problems occur, you can systematically diagnose them rather than treating the RTOS as a black box.
• Most importantly, you help us build a reliable, secure, maintainable, testable, and production-grade Zephyr platform suitable for demanding and regulated embedded products.

Our Hiring Approach

We hire for demonstrated technical capability, relevant hands-on experience, problem-solving ability, and engineering ownership. A formal degree can be valuable, but equivalent practical experience is welcome where a degree is not essential to performing the work.

Sibiu, Romania | Remote | Full-Time Employment. No B2B, freelance, consulting, or independent-contractor arrangements. If you have spent years working deep inside Zephyr and embedded systems — and enjoy solving difficult problems where software meets hardware — we would like to talk.