Backend Kotlin Freelancer

Freelance Senior Backend Kotlin Engineer Opportunity

(3-Month Contract, Berlin– Onsite some)

We are seeking a Senior Backend Kotlin Engineer for a freelance contract from April to June (with potential extension). This role is based in Berlin, and requires some onsite presence.

About the Role

You’ll be working on cutting-edge backend systems in an agile, fast-paced environment. Our teams develop and maintain scalable, high-performance services using Kotlin, PostgreSQL, Kafka, AWS, and Kubernetes, with some Python in select areas. This is an opportunity to build impactful, in-house solutions that enhance user engagement across multiple domains, including AdTech, Promotions, and subscription-based services.

What We’re Looking For

✅ Strong experience with Kotlin - must have! (plus other JVM-based languages like Java or Scala)

✅ Solid backend development expertise, with a deep understanding of modern architectures and best practices

✅ Proven ability to break down complex projects into deliverable features, identify dependencies, and provide reliable estimates

✅ A problem-solving mindset, eager to tackle technical challenges and continuously improve solutions

✅ A team player, someone who collaborates, shares knowledge, and actively works on solutions beyond their direct remit

✅ Fluent English skills

Work Environment & Culture

You’ll be joining a dynamic, startup-style office culture where collaboration is key. We encourage engineers to step outside their comfort zones, tackle problems together, and contribute to solutions that impact millions of users.

Key Details

📆 Contract Duration: April – June 2024 (3 months, potential extension)

📍 Location: Berlin, (must be willing to travel onsite when needed)

🗣 Language: English