Senior Hardware / Firmware Engineer

Kontakt.io

. Design, write and maintain production firmware in C for Nordic Semiconductor (nRF) microcontrollers on battery-powered devices .

Posted 11/12/2026full-timeKraków • PolandSeniorWebsite

Core Competencies

Role fit

Core Competencies

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Demonstrates expertise in designing and maintaining production firmware in C for microcontrollers, with a strong focus on low-power design and device-to-cloud communication. Proficient in using lab equipment for debugging and validating hardware, alongside solid skills in Python for automation and testing.

Highest-signal resume keywords

Firmware Development In CLow-Power DesignBoard Bring-Up And DebuggingPython Scripting And AutomationMicrocontroller Experience (ARM Cortex-M)

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills

Firmware DevelopmentC ProgrammingLow-Level Driver DevelopmentBLE Feature ImplementationBootloader DevelopmentPower Management ImplementationUnit And Integration TestingDebugging On TargetSchematic ReviewPCB Layout Review

Soft Skills

CollaborationCommunicationProblem-Solving

Tools & Technologies

Nordic Semiconductor nRFAI Coding ToolsOscilloscopeLogic AnalyserPower ProfilerSoldering StationAltiumKiCad

Industry Keywords

IoTHealthcareRegulated Device EnvironmentsRF TestingEMC Pre-ComplianceCE CertificationFCC Certification

Tech Stack

Tools & technologies

CloudIoTPythonRTOS

About the role

Key responsibilities & impact

Design, write and maintain production firmware in C for Nordic Semiconductor (nRF) microcontrollers on battery-powered devices
Build and extend BLE features for indoor positioning and device-to-cloud communication
Write and debug low-level drivers for sensors and peripherals (SPI, I2C, UART, ADC)
Develop bootloader and firmware update (OTA) functionality
Implement power management including sleep modes, duty cycling and radio timing
Build watchdog, reset and device health monitoring logic
Write unit and integration tests, review teammates' code and maintain the firmware codebase
Collaborate with cloud and Location Engine teams on reliable device-to-platform data transfer
Write Python tools for testing, data analysis and automation
Use AI tools such as Claude Code to write, review and debug firmware
Review schematics and PCB layouts and propose corrections
Test and validate boards in the lab through bring-up, peripheral checks and current measurements
Use oscilloscopes, logic analysers, power profilers and soldering stations
Build and modify proof-of-concept boards
Investigate field and production issues spanning firmware, hardware, logs and component-level faults

Requirements

What you’ll need

5+ years of engineering experience on commercial hardware products
A background in electrical / electronics engineering, including hands-on work designing, testing and validating boards
Commercial firmware experience in C on microcontrollers (ARM Cortex-M or similar) — drivers, RTOS or bare-metal, debugging on target
Ability to read and review schematics and PCB layouts independently, and explain what you would change and why
Real board bring-up and debugging experience with lab equipment — oscilloscope, logic analyser, multimeter, soldering
Good understanding of low-power design and how hardware and firmware together affect battery life
Working knowledge of serial interfaces and peripherals (SPI, I2C, UART, ADC, GPIO) on both sides of the wire
Solid Python for scripting, test automation and tooling
Practical use of AI coding tools in your day-to-day work
Fluent English, spoken and written — it's our working language every day, including with colleagues in the US
Bonus: Nordic nRF experience
Bonus: Zephyr RTOS experience
Bonus: RF / wireless fundamentals — BLE, antenna matching, RF testing
Bonus: Experience with PCB design tools (Altium, KiCad or similar)
Bonus: Experience taking a device through production — DFM, test fixtures, production testing
Bonus: Exposure to certification and EMC pre-compliance (CE / FCC)
Bonus: Background in IoT, healthcare or other regulated device environments

Benefits

Comp & perks

Hybrid schedule — 2–3 days/week from our Kraków office
Meaningful equity in a company scaling fast, with real customers and real revenue
Full benefits: private healthcare, benefits platform, multisport, snack and lunch in the office
Genuine ownership — your work ships in devices running in hospitals around the world