Senior Hardware / Firmware Engineer

Backed by Goldman Sachs and trusted by leading health systems including HCA Healthcare, Sutter Health, AdventHealth, Trinity Health, Northwell Health, Cleveland Clinic, and the U.S. Department of Veterans Affairs, we’ve more than doubled our revenue and are rapidly scaling with a clear path toward $100M in annual recurring revenue.

If you're excited to solve hard problems and help health systems deliver better care, we'd love to meet you!

Senior Hardware & Firmware Engineer

Kraków · Engineering · Hybrid

About the Role

Our devices sit at the physical edge of the Kontakt.io platform — battery-powered BLE tags, badges and gateways that deliver real-time location intelligence for patients, staff and assets in hospitals worldwide. Thousands of them run in the field, in regulated healthcare environments, and they have to keep working without anyone touching them.

We're hiring a Senior Hardware & Firmware Engineer to join our Firmware team in Kraków. Most of your time will go into firmware — but we're specifically looking for someone with an electrical / electronics engineering background: someone who has designed and tested boards, brought them up, measured them and found out why they didn't work. You'll be the person who can look at a schematic or a misbehaving board and tell us what's really going on.

You won't be designing boards from scratch every day. You'll review and correct designs, test and validate boards in our own lab, and build proof-of-concept hardware when we need to try something quickly.

If you spent a few years as an electronics / hardware engineer and then moved closer to firmware because you wanted to own the whole device — this role was written with you in mind.

What You'll Do

Firmware — most of your time

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

• Build and extend BLE features used 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, and keep devices updatable safely in the field

• Implement power management in firmware — sleep modes, duty cycling, radio timing — to get the most out of every battery

• Build watchdog, reset and device health monitoring logic so devices keep running without human intervention

• Write unit and integration tests, review your teammates' code, and keep the firmware codebase maintainable

• Work with the cloud and Location Engine teams on how data gets from the device to the platform reliably

• Write Python tools for testing, data analysis and automating repetitive work

• Use AI tools (Claude Code or similar) as a real part of how you write, review and debug firmware

Hardware — review, test and prototype

• Review schematics and PCB layouts and propose corrections before boards go to production

• Test and validate boards in our lab — bring-up, peripheral checks, current measurements — using oscilloscope, logic analyser, power profiler and soldering station

• Build and modify proof-of-concept boards to try new ideas quickly

• Investigate field and production issues where firmware and hardware meet, from firmware logs down to component level

What You Have

• 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 Points If You Have

• Nordic nRF experience

• Zephyr RTOS experience

• RF / wireless fundamentals — BLE, antenna matching, RF testing

• Experience with PCB design tools (Altium, KiCad or similar)

• Experience taking a device through production — DFM, test fixtures, production testing

• Exposure to certification and EMC pre-compliance (CE / FCC)

• Background in IoT, healthcare or other regulated device environments

Perks & Benefits

• Hybrid schedule — 2–3 days/week from our Kraków office. If you enjoy working side by side with people and hardware, you'll like it here

• 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