AI Developer - LLM Applications

Reaktor's award-winning tech community is looking for AI Developers to join us in Helsinki.

If you thrive on applying cutting-edge AI technologies, building LLM-powered applications, and driving projects through the full software development lifecycle, and you're passionate about solving real human problems with a holistic approach, we'd love to meet you. Join us to experience a truly collaborative, low-hierarchy environment where your curiosity and ideas can make a real impact.

As an AI Developer at Reaktor, your job is to be an expert in a range of AI-related software development responsibilities spanning the entire software development lifecycle, from front-end to production.

Your daily tasks include:

• Designing and implementing end-to-end LLM-enabled applications from backend architecture to user-facing components, ensuring scalability and maintainability
• Integrating commercial and open source LLMs (e.g. OpenAI, Anthropic, Meta Llama) into production applications and workflows, using APIs or fine-tuning
• Working with end-to-end RAG pipelines, including embeddings, vector databases (e.g. PostgreSQL + pgvector, chromaDB, pinecone), robust prompt engineering strategies and guardrails
• Designing and implementing evaluation pipelines to benchmark model performance and safety
• Collaborating with cross-functional teams, contributing to AI use cases for complex business challenges
• Working with the client's tech and business teams and helping them pick the right technologies
• Delivering world-class technical expertise to client and team
• Other software development tasks: architecture/design, test automation, debugging

To thrive in this position, you'll need:

• Experience with AI software development technologies (LLMs, backend, frontend, ops, consulting) in production
• Experience deploying AI applications in cloud environments (Azure, AWS, GCP) with containerization (Docker, Kubernetes)
• Foundational DevOps knowledge: CI, automated deployment, test automation
• Know-how on vector databases (PostgreSQL + pgvector, pgvectorscale, chromaDB, pinecone)
• Awareness of GDPR, security, and ethical considerations with AI
• Comfortable engaging with client stakeholders
• Fluent verbal & written Finnish and English skills

Technologies in our projects:

• Python or Node.js/TypeScript with frameworks like LangChain, FastAPI, LlamaIndex
• Some projects require JVM-based languages

Why join us: Variety of industries (Healthcare, Public Sector, Industrial, Retail, Defense & Security, Aero, Gaming & Entertainment); team chooses approach/tech with the client; supportive low-hierarchy community; sustainable work-life balance with daily-life support; internal training and Cloud Academy; 300+ hobby clubs.