Embedded & Prototyping Engineer
Posted on November 19, 2025 (25 minutes ago)
Company and Role Overview
Natural Cycles is a leading women's health company that developed the world's first birth control app, used globally by millions. The company is a fast-growing startup promoting an international and ambitious working environment with colleagues based in Stockholm, Geneva, New York, and remote locations.
This role is designed for an engineer passionate about end-to-end building, comfortable with firmware, hardware prototyping, and app integration. The position reports directly to the Head of Hardware and involves prototyping, testing, and refining the next generation of wearable devices.
Key Responsibilities
Firmware Development & Optimization:
- Implement and improve sensor drivers, data collection, and low-power algorithms.
- Maintain and improve BLE communication, background updates (FOTA), and data transfer.
- Customize and structure raw logs for testing and analytics.
- Debug firmware plugins and integrate analytics for data validation.
- Profile and reduce battery consumption across operating modes.
Hardware Prototyping & Validation:
- Perform hardware modifications and assist in sensor integration or board validation.
- Contribute to test setups for endurance, temperature, and performance validation.
- Support design iterations including materials, ergonomics, and assembly feedback.
- Participate in certification and compliance efforts.
App & Tooling Collaboration:
- Use code generation tools to develop, extend or debug iOS and Android apps.
- Prototype app-side visualizations.
- Collaborate with software engineers to verify firmware to app data flows.
- Contribute to automation and data validation pipelines as needed.
Skills and Experience Required
- 3 to 5 years of experience in embedded systems, firmware, or electrical engineering.
- Proficiency in C/C++ and familiarity with ARM-based MCUs (e.g., nRF52, STM32, CC2642).
- Experience with BLE, sensor interfacing (I²C/SPI), and low-power design.
- Comfort with hardware tools like oscilloscopes, soldering, basic rework, and prototype bring-up.
- Interest in AI-assisted development tools for firmware and app experiments.
- Experimental mindset focused on early testing, measuring results, and rapid iteration.
Bonus Points:
- Familiarity with data analysis and app analytics.
- Experience with Swift (iOS), Kotlin (Android), or cross-platform frameworks such as Ionic or React Native.
- Exposure to temperature or optical sensing systems.
- Understanding of wearable power management and BLE stack tuning.
- Curiosity about digital health, female physiology, or biometric sensing.
Why You Will Love It Here
- Work directly with Natural Cycles’ Head of Hardware on wearable development.
- Freedom to experiment from firmware to hardware to app-level.
- Use modern tools and conduct real-world R&D with clear objectives and goals.
- Join a small, deeply technical team where ideas move fast and impact is tangible.
Location and Remote Work
This position is officially based in Stockholm, Sweden, but is fully remote. Collaboration will be close with the Head of Hardware located in Stockholm. Relocation support is offered for candidates not currently living in Sweden.
How to Apply
To apply, upload your CV and answer the questions on the application form available on the career site. Applications sent via email are not accepted due to GDPR, and only applications submitted through the career site in English will be considered.
Natural Cycles values diversity and inclusion and welcomes candidates from all backgrounds. They emphasize creating an inclusive environment for all employees and candidates.
Note: They are not looking for consultants or assistance from recruitment agencies.
Application Process
To apply, just upload your CV and answer the questions on the application form. Applications via email cannot be accepted due to GDPR, and only applications submitted via the career site (in English) will be considered.
Diversity and Inclusion
Natural Cycles values diversity and inclusion, recognizing that diverse teams are stronger. They welcome candidates from all walks of life and are committed to creating an inclusive environment for all employees and candidates.
Additional Note
Note that they do not seek consultants or help from recruitment agencies.