Freelance Senior Backend Engineer - Kotlin (m/f/d)

voize; Deutschland; Remote; EUR 83,000 - 152,000; Full time

Benefits offered by this job

Travel expenses covered

Remote work

Job summary

voize is seeking a Freelance Senior Backend Engineer for the German Market squad. You will ensure seamless data flow between voize and partners’ software, building and maintaining integrations with healthcare platforms. You can be based remotely across Germany, France, or the UK.

Your role involves shaping integrations, building scalable APIs, and owning end-to-end development—from idea to deployment—while designing future-proof architectures that save caregivers time and improve documentation.

Qualifications

• Proven backend development experience with API integrations.
• Excellent Kotlin proficiency.
• Strong design and implementation of RESTful APIs.
• Fluent German language skills (C1) for partner communication.
• Willingness to travel to Berlin (expenses covered).

Responsibilities

• Shape integrations that connect voize with care and medical sector systems.
• Develop and maintain scalable APIs and industry-standard interfaces.
• Own end-to-end integration projects from idea to deployment.
• Design data models and robust architectures for complex systems.
• Contribute to time-saving, documentation-improving workflows for frontline workers.

Skills

Kotlin

Backend development

API integration

REST API

German (C1)

Travel willingness

Job description

Why voize? Because we’re more than just a job!

At voize, we believe the greatest gift to frontline workers is time - time to care, connect, and be present. Today, that time is lost to admin work that pulls nurses away from what matters most: people.

Your Mission

As a Freelance Senior Backend Engineer for our German Market squad, you’ll ensure that data flows smoothly between our products and our partners' software solutions. You’ll build and maintain the integrations that connect the voize with senior care and hospital software platforms. We are open for you to be based remotely across Germany, France or the UK.

Your Daily Business - No two days are alike

• Shape the future of our integrations - Develop interfaces that seamlessly connect voize with systems in the care and medical sector
• Build future-proof solutions - Develop a scalable API, set industry standards, and work closely with partners and clients
• Take end-to-end ownership - From the idea and implementation to the ongoing development of our integrations
• Architecture with foresight - Design thoughtful data models and sustainable solutions for complex systems
• Work with impact - Your work saves caregivers time, improves documentation, and supports people who do amazing work every day.

Your Skillset - What you bring to the table

• Several years of experience in backend development and API integration
• Excellent proficiency with Kotlin
• API design and development with REST
• Fluent in German (C1) to communicate effectively with partners
• Willingness and work authorisation to travel to Berlin (we cover your expenses!)
• Can work with us for minimum 3+ months

Ready to talk?

We look forward to your application and can’t wait to meet you - no matter who you are or what background you have!