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# Firmware Engineer

- **Company:** termios GmbH
- **Location:** Düsseldorf, Germany
- **Experience:** Expert
- **Salary:** €65,000.0 - €85,000.0
- **Contract:** Permanent contract
- **Skills:** Data Analysis, ARM Architecture, Automation of Tests, Communications Protocols, Software Debugging, Firmware, Hardware-In-The-Loop Simulation, Joint Test Action (IEEE Standards), Python (Programming Language), Real-Time Operating Systems, LoRaWaN, Toolchain, Universal Asynchronous Receiver/Transmitter, Serial Peripheral Interface, Backend, Bare Metal, Hardware Debugging
- **Published:** November 1, 2026
- **Apply:** https://www.careerjet.de/jobad/defb85df4f7e504a3458240321546b0645

## About the Role

Must-haves:
5+ years embedded/firmware development in C / C embedded
ARM Cortex-M architecture (bare-metal and/or RTOS)
Experience in Low-power design and energy efficiency
Knowledge of common communication protocols such as UART, I2C, SPI and hardware debugging: JTAG/SWD, logic analyzer, oscilloscope
Python for test automation and data analysis
Embedded security fundamentals
Degree in related engineering field
Nice-to-have:
LoRaWAN hands-on (SX127x/SX126x, ChirpStack)
NXP MCUXpresso SDK and toolchain
Experience in other main-stream programming languages like Python, Go or Algol 68
OverTheAirUpdate in embedded context
Regulatory background (RED, CRA)

## Description

termios builds smart thermostats for real estate. Our product - termios Pro - replaces standard radiator thermostats in existing buildings, performs hydraulic balancing via a self-learning algorithm, and cuts heating energy consumption by up to 30%. No battery, no retrofitting: the device harvests energy from the temperature differential between radiator and room air (thermo-harvesting) and communicates over LoRaWAN.
The system runs at scale across multi-unit residential portfolios. Each thermostat is a constrained embedded device operating autonomously, syncing state through a LoRaWAN gateway to a cloud backend that runs the optimization logic. We're 35 people, growing, and the firmware team is small - your work ships directly to devices in real apartments.
Tasks
The firmware running on our smart thermostats - from first commit to field rollout. You write code, solder, measure, debug. No handoffs to someone else when it gets hard.
Thermostat firmware development and optimization
LoRaWAN communication stack (implementation + maintenance)
Low-power / energy harvesting optimization
OTA update mechanisms
Automated Hardware-in-the-loop test infrastructure (build, operate, extend)
Release process, Definition of Done, RED/CRA compliance
Field monitoring dashboards and post-rollout quality