(Senior) Fullstack Software Engineer - Ruby/ Typescript (m/f/d)

1KOMMA5° is dedicated to creating a sustainable energy system with a focus on renewable technologies. The Senior Fullstack Software Engineer will be responsible for developing and maintaining the core Rails application and leading technical implementations for complex projects, contributing to the energy transition in private homes and small businesses worldwide.

Responsibilities:

• Develop and maintain the core Rails application with a focus on code health, modern patterns, and long-term stability
• Lead technical implementation for complex projects within 6-week cycles, taking ownership from architectural design to shipping
• Build pragmatic connections between the Rails monolith and satellite TypeScript/GCP services (Pub/Sub, Cloud Functions) without over-engineering
• Proactively identify and resolve friction in tooling, CI/CD, and local environments to ensure the codebase remains enjoyable to work in
• Drive high-quality async collaboration through clear documentation, architectural decision records (ADRs or RFCs), and comprehensive code reviews

Requirements:

• proven experience in writing maintainable, self-describing, reusable and testable code with Rails and other major back-end or full-stack technologies in several past projects
• experience designing and maintaining RESTful APIs
• experience with measuring and improving performance
• an agile and result-oriented mindset and a passion to support your team colleagues
• interest or experience in human-centered software development
• excellent knowledge of spoken and written English, German is a plus
• residency in Germany