Senior Backend & AI Engineer (all identities)

Das erwartet Dich Build intelligent backend systems that make a genuine impact in healthcare. Caspar Health is the leading digital platform for medical rehabilitation. We empower doctors, therapists, and nursing staff to care for patients as quickly, effectively, and sustainably as possible. To take our platform to the next level, we are expanding our small, highly agile backend squad (consisting of 3 engineers and a Product Manager). In this role, you will take full technological ownership: from designing robust Ruby on Rails services and clean API architectures to building LLM-based agent workflows with repeatable quality checks. If you are passionate about combining modern AI engineering with true purpose and highest software standards, you will thrive here. We appreciate your expertise and wish to provide full transparency regarding the compensation range for this role. Your starting salary will be aligned with your qualifications, relevant experience, skill set, and market benchmarks. Remuneration for this position follows our internal salary bands and ranges from €78,000 to €88,000 gross annually (based on a full-time 40-hour work week). This role is located in Germany and requires full physical presence within the country. Due to our existing payroll and social security framework, permanent remote employment from abroad is not supported. Candidates must be eligible to work in Germany and resident from their first day. Please be advised that we cannot offer visa sponsorship or relocation assistance at this time. Deine Herausforderungen • System Architecture: Full end-to-end ownership of your features across implementation, automated testing, release, and live operation. • Backend Engineering: Development of scalable Ruby on Rails services, robust APIs, data models, and background jobs including authorization and billing workflows. • LLM Workflows: Building and optimizing LLM applications, evaluation pipelines, and agent workflows with repeatable quality checks. • Product Collaboration: Close partnership with Product Manager and domain experts to turn complex requirements into maintainable, high-performance software. • Technical Reviews: Active contribution through clear technical reviews, operational monitoring, and explicit technical decision-making. • Quality Standards: Shaping our shared delivery practices and establishing modern test and engineering standards across the team. Dein Profil • Backend Engineering: Strong senior experience in building and maintaining complex systems using Ruby on Rails . • API Design: Proven expertise in designing clean APIs, data models, and managing background job processing. • System Architecture: Sound understanding of authorization concepts, billing workflows, and automated testing strategies. • LLM Practice: Practical experience building LLM applications, evaluations, and agent workflows. • End-to-End Ownership: Ability and mindset to own functionality independently from initial design to live production. • Technical Communication: Strong communication skills to collaborate with product and domain experts and make technical trade-offs explicit. Warum 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, no egos. After all, we’re all working toward the same vision. #ValueFocus! Access to all Caspar offerings for mental and physical well-being #HealthyTogether! And yes – all the snacks your heart desires, group sports sessions, a never-empty drinks fridge, and a healthy dose of humor are included too What defines us as a team We live diversity – it's not a marketing slogan, it's part of our everyday reality Feedback isn’t a tool – it’s part of our culture We believe that technology only makes sense when it truly helps people Our drive is purpose – but our standard is professionalism Find more English Speaking Jobs in Germany on Arbeitnow