Senior Firmware Engineer

ABOUT TIN CAN Tin Can is building a safer, simpler way for kids to connect — without smartphones. We're creating screen-free, delightful devices and services that let families call the people who matter most, free from the noise of today's digital world. We're building a bold, authentic, nostalgic, and kinda quirky brand that resonates with folks who want something simpler & better for their kids than the tech-infused lives we're currently living (and who have a sense of humor about it). As we gear up to scale to thousands of families, we're ready to bring on an engineer to help make it happen. THE ROLE We're looking for a Senior Firmware Engineer to own the software that lives on every Tin Can. Our devices are the front line of the experience families feel most — how clearly a call sounds, and whether the phone just works when a kid picks it up to call Grandma. The firmware runs on ESP32 hardware and powers everything from connecting to Wi-Fi to placing a call to 911. You'll be the person the rest of engineering turns to on anything device-side: how firmware gets better, how we ship updates safely across our fleet, and how we understand and improve the real-world experience of every call. You'll set firmware direction and coordinate the firmware and hardware work, so device-side expertise and ownership live with us. You'll work closely with our voice, IoT, and app engineers as we design and ship the next generation of devices. This is a hands-on role for someone who cares about the details families feel — and wants to own them end to end. WHAT YOU'LL DO - Own our device firmware end to end (C/C++ on ESP32) — connectivity, provisioning, call behavior, and on-device audio - Make over-the-air updates safe and boring: phased, reversible rollouts you'd trust across the whole fleet, sensible versioning (which builds reach which devices), monitoring for updates that succeed or fail, and recovery for devices that fall out of the update path - Improve how real calls actually sound, working across the on-device audio path — echo cancellation, jitter buffer, packet-loss concealment, and codecs - Chase down the field issues families feel — devices dropping off Wi-Fi, mesh and dual-band quirks, dropped calls — and drive them to root cause - Instrument the fleet so we can see the kid's-eye experience: is the phone reachable, does the call connect, how does it sound, did it drop - Set firmware direction and coordinate the firmware and hardware work, so device-side knowledge and ownership live with the team - Partner across the hardware line — reviewing specs and supporting board bring-up so firmware and hardware decisions account for each other on current and next-gen devices WHAT WE'RE LOOKING FOR - 5+ years building and shipping firmware for connected devices, ideally in C/C++ on resource-constrained microcontrollers (ESP32/Espressif a big plus) - You've shipped firmware to real devices in the field and owned over-the-air updates — staged rollouts, versioning, and failure recovery — at meaningful scale - Comfortable debugging across the software/hardware boundary: reading schematics, reaching for a scope or logic analyzer, and reasoning about audio (I2S), Wi-Fi/BLE, power, and reset behavior - A reliability mindset — you think in terms of what's reproducible, testable, and reversible, and you instrument things so you know what's really happening in the field - A clear communicator who writes things down, because you want the whole team to understand the systems you build - A collaborative, low-ego approach — everyone here sweeps the floor - Bonus: real-time audio or VoIP experience (SIP/RTP, codecs, AEC, jitter buffer, PLC); an IoT fleet platform like Thingsboard; Wi-Fi provisioning (BLE/BluFi) and mesh-network depth; or taking a consumer hardware product from prototype through the factory - Extra bonus: electrical engineering chops — schematic capture, PCB bring-up, or audio hardware design — that let you flex between firmware and elect…