Senior Java Backend Engineer (m/f/x)

About osapiens At osapiens, more than 550 talented minds unite around one mission: enabling sustainable growth for businesses worldwide. Founded in 2018 and headquartered in Mannheim, Germany, we have built the AI-driven osapiens HUB - a multi-tenant platform hosting 26 enterprise-grade solutions designed for cross-company collaboration, automation, and compliance. With offices across Europe and the US, we are shaping the future of scalable and secure business technology. Your Team Our Backend Engineers (Hybrid in Mannheim · 3 days/week on-site) build the foundation of the osapiens HUB - the cloud platform powering all our SaaS products. The team develops engines for seamless monitoring, real-time data processing, centralized integration, automated workflows, and dynamic app development. Simply put: they build the core technologies that enable global companies to turn compliance into efficiency and sustainable growth. Your Key Responsibilities Build Scalable Systems : Design and develop reliable backend systems using Java and modern technologies to power the osapiens HUB. Develop Core Logic : Implement business logic for enterprise-grade solutions and solve complex real-world challenges. Integrate Platforms : Build and maintain RESTful and GraphQL services that support seamless integrations and client needs. Collaborate End-to-End : Work with engineers, product managers, and designers to deliver integrated, high-quality solutions. Mentor & Elevate Quality : Support junior engineers and promote best practices in coding, testing, and backend development. Your Experience Passion for Scalable Systems : You’re motivated by building distributed, high-performance backend systems that create real-world impact. Java & Spring Expertise : Strong experience with Java/JavaEE and Spring Framework, with deep knowledge of scalable backend architectures. Database & API S kills: Familiarity with NoSQL databases (e.g., Cassandra, ScyllaDB) and strong experience designing RESTful and GraphQL APIs. Quality & Reliability : Proficiency in automated testing, CI/CD practices, and building fault-tolerant distributed systems. Modern Engineering Toolkit : Experience with OpenSearch or Elasticsearch, solid Git skills, an agile mindset, and exposure to DevOps practices. Join us for this and more... A purpose-driven mission tackling complex sustainability challenges while working alongside global industry pioneers at a fast-growing unicorn company Room for creativity through collaborative teamwork and an open communication culture Flexibility and team bonding with our hybrid work options Fuel for your growth journey, both personally and professionally Sustainable mobility options, promoting eco-friendly commuting solutions Fun team events and outings with our global teams Inspiring workspaces in Mannheim and beyond