4ff · 1 day ago
Embedded Firmware Engineer
Palo Alto, CA
Contract
Hybrid
Mid Level
$75/hr - $120/hr4ff is a startup based between Silicon Valley and Shenzhen, focusing on building unique AI hardware and software. They are currently seeking an Embedded Firmware Engineer to develop firmware for their product, muse, which is a minimalist ring that utilizes voice as a primary interface.
Computer Software
Responsibilities
Shipped BLE firmware end-to-end on a battery device (pairing, bonding, reconnect edge cases, iOS quirks)
Strong embedded C (C++ is a plus plus), comfortable with tight ram/flash constraints
Worked with Nordic chipsets
New board bring-up: GPIO, clocks, interrupts, timers, reading schematics
Debugging skills: SWD/J-Link, logging, logic analyzer/scope
Power discipline: deep sleep, wake sources, BLE parameter tuning for stability vs battery
Audio + mic experience (streaming & on-device recording, buffering)
You move fast, but you don't accept shipping shitty firmware
Qualification
Required
You've shipped embedded BLE firmware end-to-end before
Shipped BLE firmware end-to-end on a battery device (pairing, bonding, reconnect edge cases, iOS quirks)
Strong embedded C (C++ is a plus plus), comfortable with tight ram/flash constraints
Worked with Nordic chipsets
New board bring-up: GPIO, clocks, interrupts, timers, reading schematics
Debugging skills: SWD/J-Link, logging, logic analyzer/scope
Power discipline: deep sleep, wake sources, BLE parameter tuning for stability vs battery
Audio + mic experience (streaming & on-device recording, buffering)
You move fast, but you don't accept shipping shitty firmware
Benefits
Opportunity for full-time role with equity after freelancing period.
Company
4ff
4ff builds different. abyss - 02.2026. muse - 03.2026.
Founded in 2025
2-10 employees
Funding
Current Stage
Early StageCompany data provided by crunchbase