Firmware Engineer

Build the Future of Brain Health at Marbles Health

Marbles Health

portable brain-stimulation hardware (tES)

We’re shipping real, regulated tech (medical-grade reliability) and scaling fast. If you want your code to touch patients’ lives, not just dashboards, this is your moment.

What you'll do (owner, not operator)

• Design & ship firmware

  for

  ESP32-based

  devices (ESP-IDF) and lead a migration to

  lower-power MCUs

  (e.g., STM32/nRF) for longer battery life and medical reliability.
• Work close to the metal:

  FreeRTOS

  , ISR design, peripherals, timers, DMA, power states, watchdogs, and OTA.
• Integrate & optimize

  sensors and BLE/Bluetooth stacks

  for robust, low-latency comms.
• Build

  Python-based test harnesses

  and CI hooks to automate validation and regression.
• Ruthlessly

  debug, profile, and harden

  for field conditions (jitter, brownouts, RF noise).
• Collaborate with

  neuroscientists, psychologists, and game designers

  to bring therapeutic experiences to life.

Your toolkit (must-haves)

• Strong

  C/C++

  with

  ESP-IDF

  (or STM32 Cube) and

  FreeRTOS

  .
• Comfortable with

  CMake

  ,

  Git

  , structured logging, and trace-driven debugging.

• Python

  for test automation & build tooling.
• Clean code habits: documentation, interfaces, and repeatable builds.

Nice-to-haves (help you fly)

• BLE/Bluetooth LE stack experience (GATT/GAP, bonding, throughput tuning).
• Power optimization (sleep states, DVFS, radio duty cycling).
• Firmware security basics (secure boot, signing, DFU/OTA safety).
• Experience with medical/regulated products (IEC 60601, ISO 13485) or hardware bring-up (JTAG/SWD, oscilloscopes, logic analyzers).

What success looks like (30/60/90)

• 30 days:

  Build, flash, and run end-to-end on target; add tests for a critical peripheral; land a measurable power-saving win.

• 60 days:

  Own a subsystem (BLE, sampling, or power) and ship a stable OTA to field devices.

• 90 days:

  Lead the

  MCU migration plan

  (or a major performance refactor) with benchmarks, test coverage, and a rollback path.

Why this team / why now

• Frontier + impact:

  Your firmware directly enables evidence-based brain therapies.

• Ship fast, ship right:

  Startup velocity with clinical seriousness.

• Cross-disciplinary:

  Daily collisions with science, design, and product—not silos.

• Career compounding:

  Work with founders and take true product ownership.

Location: