Senior Android Developer – BLE & Hardware (Freelance)

About the role

We are looking for a senior Android developer who lives and breathes Bluetooth Low Energy (BLE) and enjoys turning Kotlin code into real-world hardware interactions. The position is freelance, time-and-material, and fully remote, with the possibility to join our core team on a permanent contract after a successful trial.

Key responsibilities

• Design, develop and maintain Android applications that communicate with peripheral devices over BLE.
• Write clean, performant, and reusable Kotlin code that can be easily maintained by other engineers.
• Participate in specification, planning and estimation of new modules and features.
• Implement unit tests and adopt a test-driven development mindset where appropriate.
• Review pull requests and provide constructive feedback to teammates.
• Identify and resolve performance bottlenecks and device-specific bugs, including OEM quirks.
• Share knowledge through tech talks, documentation, pair programming, and other formats.
• Leverage AI-based development tools as part of the daily workflow.

Required profile

• Strong ownership of the code you touch and willingness to ask “why” before “how”.
• Comfortable working in a flexible, fully remote environment with occasional meetings in CET hours.
• Curiosity about the hardware side of mobile products and a desire to improve the user experience of connected devices.
• Ability to communicate clearly and give straight‑forward feedback when challenges arise.

Required skills

• Android development with Kotlin.
• Experience with Bluetooth Low Energy (BLE) communication.
• Unit testing and familiarity with test‑driven development (TDD) practices.

What we offer

• Hourly rate of 90‑180 PLN net (B2B) depending on experience.
• Truly flexible working hours; you organise your own day.
• Fully remote work with optional access to a pet‑friendly office in Warsaw or coworking space in Gdansk.
• Potential path to a permanent contract with full benefits after a successful trial period.