Cloud Engineer - Quantum Computing (f/m/d)

eleQtron develops and operates full-stack quantum computers based on trapped-ion technology. Quantum computing is a new computing paradigm rapidly approaching commercial viability. Our unique approach combines laser-cooled trapped ions with microwave control and tailored magnetic fields. Our next-generation computing machines under development will be able to find solutions to problems that are out of reach today, thus enabling new innovative products and services for a brighter future. We are looking for a Cloud Engineer (m/f/d) to join us in Hamburg or Siegen and build and operate the scalable, secure cloud platform that connects users with our trapped-ion quantum computers. Responsibilities: You will join our Quantum firmware Team as a Cloud Engineer. You will build the layer through which the world reaches our quantum computers. Users submit quantum programs; your services compile, schedule, and dispatch them to our machines and return the results: • Build and operate the cloud services that let users submit quantum programs to our systems and retrieve their results. • Develop and deploy our compilation pipeline as a scalable cloud service , from circuit input through transpilation down to hardware-level instructions • Design and maintain the public API and SDK entry points to our platform • Implement job queuing, scheduling, and dispatch towards the hardware backends, including quota, prioritisation, and result handling • Own authentication and authorisation across the platform: user and tenant identity, API keys and tokens, and role-based access to machines, jobs, and results, built on an established identity provider rather than from scratch • Guarantee tenant isolation, so that quantum programs and results are never visible across customer boundaries, and manage secrets and credentials across the stack • Work with the quantum firmware and hardware teams on the interfaces between cloud services and the machine itself • Instrument the platform for observability and keep an eye on latency, throughput, and cost Required Skills: • 3+ years of hands-on experience building and deploying backend or platform services in production • Strong Python; additional systems-level language experience (Go, Rust, C++) is welcome • Solid API design skills (REST and/or gRPC) for services other developers have to use • Practical experience implementing authentication and authorisation in production systems: OAuth 2.0 / OpenID Connect, token handling, and role-based access control • Secure engineering habits: least privilege by default, proper secrets management, and awareness of dependency and container supply-chain risks • Infrastructure as code (Terraform, Pulumi, or similar) and CI/CD pipelines (GitLab CI, GitHub Actions, or similar) • Working understanding of GDPR and data residency requirements, and a genuine interest in digital sovereignty • Ability to collaborate effectively with experimental physicists and engineers • Strong adaptability and a quick learning mindset • Good proficiency in English (written and spoken); German is an advantage for working with public-sector partners Nice to have (Bonus) • Running an identity provider in production (Keycloak, Zitadel, Ory, Authentik, or a managed IAM service) • Multi-tenant isolation patterns in SaaS platforms • Contributing to security certification work (ISO 27001, BSI IT-Grundschutz, BSI C5) or acting on penetration test findings • Familiarity with quantum SDKs and toolchains (Qiskit, Cirq, PennyLane, QIR) or hardware abstraction interfaces such as QDMI • Batch scheduling or HPC environments (Slurm or similar) • Observability stacks such as Prometheus, Grafana, or OpenTelemetry • Prior exposure to quantum computing or other deep-tech domains What you can expec