Junior Hardware Engineer – Sensors & Prototyping

HairFit is developing a professional-grade hair sensing device designed to measure physical properties of hair and turn them into meaningful, objective data.
We are looking for a hands-on Junior Hardware Engineer to work directly on the development, testing and improvement of our prototype.
Your tasks will include:

• Building, assembling and iterating electronic prototypes
• Soldering components, connectors, wires and prototype PCBs
• Integrating and testing sensors and other electronic components
• Working with microcontrollers and data-acquisition electronics
• Troubleshooting and debugging hardware and electrical issues
• Testing different sensors, components and prototype configurations
• Setting up repeatable physical measurements and calibration procedures
• Investigating measurement noise, inconsistencies and sources of error
• Running experiments across different hair samples and documenting the results
• Supporting PCB, wiring and electronic design improvements
• Working alongside our software/data work to reliably capture and process sensor measurements
• Helping move the HairFit device from an early prototype toward a robust and repeatable system

We are primarily looking for a recent graduate or someone close to completing a degree in Electrical Engineering, Electronics, Mechatronics, Embedded Systems, Sensor/Measurement Technology, Engineering Physics, Biomedical Engineering, or a related field.
You should enjoy working hands-on with real hardware and be comfortable building, testing and troubleshooting things yourself.
Experience in some of the following would be particularly valuable:
Soldering and electronics assembly
Breadboarding and electronic prototyping
Sensors and sensor integration
Microcontrollers such as Arduino, ESP32, STM32 or similar
Reading schematics and electronic component datasheets
Analog and digital electronics
Using multimeters, oscilloscopes or other laboratory equipment
Data acquisition, ADCs and measurement systems
Basic PCB design or PCB assembly
Embedded programming in C/C++ or similar
Python for collecting or analysing experimental data
CAD, 3D printing or mechanical prototyping
You do not need experience with everything listed above. University projects, thesis work, robotics, Formula Student, internships and personal electronics projects are all relevant.
More than anything, we are looking for someone curious, practical and excited about solving problems at the intersection of hardware, sensors and physical measurement.

A paid, full-time opportunity in Berlin
Significant technical ownership from an early stage
The opportunity to work directly on the core technology behind HairFit
Hands-on experience developing a new physical product from prototype onward
Close collaboration with the founder and technical team
Freedom to experiment, test ideas and influence engineering decisions
Exposure to hardware, sensor technology, data collection and product development
An environment where your work can have a direct and visible impact on the product
HairFit is still at an early stage, so this role is particularly suited to someone who wants responsibility early in their career rather than working on one small component within a large engineering organization.

Please send us your CV along with a short introduction about yourself.
We would particularly like to hear about one hardware, electronics or engineering project you have personally worked on. Tell us what you built, what your role was and one technical problem you had to solve.
Personal projects, university projects and prototypes are very welcome — we care about what you can build, not just previous job titles.
Please send your application to:
rasanebabalwa@gmail.com
Subject: Junior Hardware Engineer – HairFit