Job detail for Firmware Engineer

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

Requirements
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
in embedded context
Regulatory background (RED, CRA)
IoT in building tech or energy sector

Don't tick every box? Apply anyway.
Benefits

Remote-friendly, output-driven company
Flexible working hours
regular team-events
dynamic tech-startup culture

We are a 35-person company — short path to decision-makers, real ownership
Hard problems: thermo management, energy harvesting, LoRaWAN at scale, OTA in the field
Every line of code runs on real devices in real homes and make real change.
No cover letter. CV + GitHub / project links if available.
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