Senior Backend Engineer RoR (all identities)

What to Expect Caspar Health is the digital rehabilitation clinic with the vision of giving every patient access to the most effective rehabilitation treatment anywhere at any time. We provide individual, digital therapy combined with personal therapeutic care from healthcare professionals. This is your opportunity to help shape traditional healthcare concepts in the areas of prevention and rehabilitation so that people receive the best possible care during and after their clinic stay, regardless of their location. We are looking for a Senior Backend Engineer (all identities) to join our team in Berlin. It is an exciting time to work at Caspar because you will be the one designing how our patients will use the app in the future. You are a fit for this role if… You own the Product , not just the Ticket: You think in solutions, not tasks, and build backend architectures that solve real-world patient needs You are an AI-Native Engineer : You’ve mastered LLMs and Multi-Agent setups as strategic tools to accelerate development and stay ahead of the curve You bridge the Stack: You are a Backend expert who naturally understands Mobile constraints, ensuring seamless performance from the API to the device Your Challenges Forget ticket-punching. We’re looking for someone to take ownership of our core ecosystem: Architectural & Backend Engineering: You will design, build, and improve high-performance APIs and services that power the Caspar Health app, ensuring scalability, resilience, and operational excellence. AI Frontier : We don’t just talk about AI; we build with it. You will design, build, and improve LLM-powered workflows and contribute to developing a multi-agent environment to enhance engineering productivity and efficiency. Cross-Functional Collaboration: You will partner with Product, UX, DevOps, and Engineering teams to deliver robust solutions and contribute to technical discussions, architecture decisions, and engineering best practices. Raising the Bar: You will champion best practices in code quality and test automation (e.g., Cypress) Your Profile The Backend Core: You are an expert in Ruby on Rails and TypeScript, with a track record of running these stacks in high-stakes production environments Infrastructure & Scale: You have a robust understanding of PostgreSQL and are comfortable navigating AWS (Cognito), Docker, and Kubernetes Quality & Testing: You have experience with end-to-end testing frameworks (like Cypress) and guide the team in implementing best practices for test coverage and code quality The Mobile Bridge : You understand the mobile ecosystem. Experience with React Native will help you design backend architectures that harmonize perfectly with the frontend Modern Delivery: You are a proponent of continuous delivery and highly experienced in Over-the-Air (OTA) updates, ensuring a seamless experience for our patients AI-Native Mindset: You already use LLMs as a force multiplier in your daily coding and have a clear vision for how autonomous agents can transform software development Collaborative Challenger & Communicator: You don’t just execute; you elevate. Driven by a proactive "can-do" attitude, you thrive on challenging the status quo to drive mutual growth. As a true team player, you bridge the gap between high-level tech and business value, translating complex concepts into clear, compelling narratives for non-technical stakeholders Why Caspar Health? Remote-first with flexible working hours – office optional in Berlin-Mitte or up to 90 days a year outside of Germany To match this, we support you with a monthly home office allowance and an additional meal subsidy Plenty of time to recharge – with 30 vacation days per year Budget for learning & development, conferences, and coaching – tailored to your potential and growth opportunities. High level of ownership and decision-making freedom – no micromanagement. We hire experts who know what they’re doing. #MakeAnImpact! Genuine collaboration – no silos,