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

voize; Berlin; Remote; EUR 96,000 - 152,000; Full time

Job summary

voize is seeking a Freelance Senior Backend Engineer for our German Market squad. You will ensure data flows between voize and partners' software, building integrations that connect voize with senior care and hospital platforms.

We are open to you working remotely across Germany, France or the UK. Take end-to-end ownership of integrations, design scalable APIs, and collaborate with partners to implement robust solutions.

Qualifications

• Several years of backend development and API integration experience.
• Excellent proficiency with Kotlin.
• API design and development with REST.
• Fluent in German (C1) to communicate with partners.
• Willingness and travel authorization to Berlin (expenses covered).
• Can work with us for a minimum of 3+ months.

Responsibilities

• Shape and maintain integrations that connect voize with care and medical sector software.
• Build a scalable API and set industry standards for partner integrations.
• Own end-to-end delivery from concept to production.
• Design thoughtful data models for complex systems and scalable solutions.
• Work with impact by saving caregivers time and improving documentation.

Skills

Backend development

API integration

Kotlin

REST API design

German (C1)

Travel to Berlin

Freelance / contract work

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!