Senior Software Engineer (Rails)

At 8returns, we’re transforming one of the most frustrating, environmentally damaging, and costly aspects of e-commerce: returns. As a Backend Software Engineer at 8returns, you’ll own the systems that make our product fast, reliable, and scalable. You'll build the foundation that turns returns chaos into margin protection.

• Ship new backend features with Rails and PostgreSQL
• Design and maintain APIs that power our frontend and external integrations
• Improve performance, reliability, and developer experience across the stack
• Own core data models and workflows that merchants rely on daily
• Debug and fix issues quickly, but always aim to build long-term solutions
• Explore ways to integrate AI/automation to make systems smarter and faster
• Work closely with founders and PM to prioritize what matters most

• 3+ years building production web apps with Rails
• Strong database skills (PostgreSQL, schema design, query optimization)
• Solid understanding of backend architecture and API design
• You’re pragmatic — you solve problems, not just write code
• Comfortable with ambiguity and tradeoffs; you keep moving
• Autonomous. We give you problems, not solutions
• Bonus points if you’ve worked in an early-stage SaaS startup or as a founder
• You know your way around Heroku / AWS / infrastructure basics
• You’ve dabbled in AI/LLMs (OpenAI, Claude, LangChain, etc.)
• You can jump into React/TypeScript when needed

• Direct impact on millions of users
• Own what you build, no layers of approval
• Low-meetings, high-ownership culture
• Work directly with the founders
• Berlin-based, flexible hybrid setup
• Meaningful equity in a profitable, fast-growing company