Senior Backend Developer

About the Company

Fortnox helps companies start, grow, and develop. With smart technical solutions for businesses and accounting firms, smooth financing, and an ecosystem of strong partnerships, Fortnox is a hub for entrepreneurship in Sweden.

Responsibilities

• Build business-critical systems and scalable backend services
• Develop well-defined APIs and normalized database schemas
• Design secure, high-performance, and sustainable architectures
• Work with large language models, classification, and generative AI
• Package and deploy code in containerized environments

Requirements

• At least 5 years of professional experience building systems in Python
• Deep understanding of SQL and relational databases (e.g., PostgreSQL)
• Expertise in Docker and containerization
• Experience with Kubernetes for deploying and scaling services
• Proficiency in using AI-assisted development tools like Claude Code, Cursor, or GitHub Copilot
• Strong ability to code manually and troubleshoot complex logic without AI assistance

Preferred Qualifications

• Genuine interest in AI and Machine Learning
• Experience with platforms like Hugging Face
• Familiarity with tools like vLLM for model inference