WE WORK 6 DAYS A WEEK and we ping each other in the night.

Noso (YC S25) builds AI tools for the trades. NoWare is our hardware line. The first product is an indoor air quality sensor that HVAC contractors leave in the home: a small cube that tracks VOCs, CO2, temperature, humidity, and light, shows air quality on a glanceable LED, and streams readings to Noso over Zigbee and BLE.

That data is how contractors stay in the home after the job. It proves the system is working, flags humidity, ventilation, and filtration problems early, and turns them into tune-up, IAQ, and replacement opportunities that Noso hands to the sales team at the right moment.

We're hiring our first Hardware Engineer to own NoWare end to end: the board, the firmware, the radio, the enclosure, the install, and the pipeline that turns raw sensor readings into something a homeowner and a tech can act on.

You will work directly with the founders and our AI team, and you will spend real time in homes and mechanical rooms watching technicians install what you built.

Before applying

• We work 6 days a week, and we also work and ping each other in the night.
• We are in office in SF, and do not have any remote options.
• We have an extremely high bar on work.
• You will spend real time on job sites installing sensors next to technicians.
• If you are not okay with any of the above, DO NOT APPLY.

What You Will Do

• Take the NoWare air quality sensor from working prototype to a production run in customer homes
• Own the board: ESP32-class MCU, ENS161 VOC and SCD41 true CO2 sensors, temperature, humidity, and ambient light, LED, USB-C power, and the KiCad design behind it
• Own the firmware in C on ESP-IDF: sensor sampling, calibration and warm-up, LED behavior, on-device history, and browser-based firmware updates
• Make the radio reliable: Zigbee and BLE pairing that a technician can finish in minutes, plus a path to Wi-Fi or cellular for homes without a hub
• Build the data path from cube to Noso so readings, trends, and alerts land in the customer record and the tune-up pipeline automatically
• Design the next sensors that predict HVAC problems: airflow, filter loading, duct temperature split, and whatever else turns readings into a service call
• Make it survive the field: condensation, dust, heat, and months of unattended operation with no reboots
• Work with contract manufacturers on the first production run, test fixtures, and certification
• Go onsite, watch where the sensor or the install fails, and fix it the same week

Who You Are

• You have shipped a physical product or embedded device that real people used, not just a class project
• Strong in embedded C or C++, ideally on ESP-IDF or a similar RTOS, and comfortable in Python for tooling and data analysis
• You have built low-power wireless hardware with Zigbee, BLE, Thread, or Wi-Fi
• You have worked with I2C sensors, analog front ends, and know how to get clean readings out of a noisy environment
• You can design a board in KiCad, read a schematic, drive a soldering iron, and debug with a scope when something is wrong
• You have taken a device through EMC, safety, or certification, or you want to learn fast
• You want to see your hardware on a shelf in a customer home, not in a lab
• You want to work extremely hard and grow quickly

Nice to Have

• Experience with indoor air quality, smart thermostats, or home or building IoT
• Familiarity with Home Assistant, Zigbee2MQTT, or Matter
• Familiarity with HVAC systems, or time in the trades
• Experience with contract manufacturers and small production runs
• Experience running ML on microcontrollers or edge devices
• Startup or hackathon experience

You Might Not Be a Fit If

• You want a mature hardware org with a dedicated EE, ME, and firmware team
• You prefer to stay in the lab and never visit a job site
• You need a finished spec before you start building
• You are looking for a low-intensity role

Interview Process

• You complete the NoWare hardware take-home: start from the open-source AirCube board, add a PM2.5 sensor and cellular with a SIM card, remove Zigbee, write the firmware, and get it working on real hardware
• Once your PCB design is finished, we cover the production cost of your board
• When it works, you book your founder interviews: one with Winston, CEO of the company, and one with Alex, CTO of the company, each walking through your build
• You come onsite and ensure the team likes you

Why Join

This is a chance to be the first hardware hire at an early-stage company and define what Noso hardware looks like, starting with the first NoWare sensor. You'll own the device, work directly with the founders, and watch technicians install what you built every day. You'll have meaningful ownership: $180K base and meaningful early-stage equity.