Senior Software Engineer (m/f/d)

Polarise; Nordrhein-Westfalen; Hybrid; EUR 70,000 - 110,000; Full time

Benefits offered by this job

Remote-first work model

Structured onboarding and hardware (e.

EU work flexibility

Germany Ticket

Job summary

Polarise is seeking a backend engineer to develop and operate core services for our Sovereign AI Cloud. You will work with Python, FastAPI, and OpenAPI, contributing to secure, scalable multi-tenant platforms.

Responsibilities include building robust data architectures with PostgreSQL and Redis, ensuring observability, and participating in CI/CD and GitOps workflows. Remote-first, international team, Hamburg/Bonn-friendly locations in Germany possible.

Qualifications

• Several years of backend development experience with at least one modern programming language.
• Solid REST API design experience and OpenAPI specifications.
• Relational database experience (PostgreSQL); Redis or similar in-memory databases.

Responsibilities

• Develop and operate core services of our Sovereign AI Cloud using Python and FastAPI, including the OpenAI-compatible LLM inference gateway and the conversational AI platform.
• Contribute to the platform library for authentication, authorization, and multi-tenancy to secure and scale products.
• Build solutions with PostgreSQL, Redis, and asynchronous Python to ensure robust data architectures.
• Ensure quality, stability, and observability via automated testing, monitoring, and logging.
• Support the full software lifecycle from architecture and implementation to deployment and production operation.
• Collaborate with product, platform, and engineering teams and contribute ideas to develop the AI platform.
• Leverage CI/CD, GitOps, and Kubernetes-based deployments for efficient and secure software delivery.

Job description

Your mission

• You develop and operate core services of our Sovereign AI Cloud based on Python and FastAPI. This includes, among other things, our OpenAI-compatible LLM inference gateway and our conversational AI platform.
• You contribute to our shared platform library for authentication, authorization, and multi-tenancy, creating the foundation for secure and scalable products.
• You build solutions using modern technologies such as PostgreSQL, Redis, and asynchronous Python, ensuring sustainable and robust data architectures.
• You are responsible for the quality, stability, and observability of your services through automated testing, monitoring, and logging solutions.
• You support the entire software lifecycle, from architecture and implementation to deployment and the operation of production systems.
• You work closely with our product, platform, and engineering teams and actively contribute your ideas to the further development of our AI platform.
• You leverage modern development practices such as CI/CD, GitOps, and Kubernetes-based deployments to deliver software efficiently and securely.

Your profile

• You have several years of experience in backend development and are proficient in at least one modern programming language. Ideally, you have hands-on experience with Python, FastAPI, Pydantic, and SQLAlchemy.
• You have solid experience in designing and developing REST APIs and working with OpenAPI specifications.
• You are confident working with relational databases, preferably PostgreSQL, and have experience with Redis or comparable in-memory databases.
• You are familiar with modern authentication and authorization concepts such as OAuth2, OIDC, JWT, and RBAC. Experience with Keycloak is a plus.
• You value clean, maintainable, and well-tested code and are comfortable working with modern development tools such as pytest, mypy, and ruff.
• You have practical experience with Git, Docker, and CI/CD pipelines.
• Ideally, you have already operated applications on Kubernetes and are familiar with GitOps approaches and tools such as Helm or ArgoCD.
• Initial experience with AI applications, LLM integrations, or modern AI toolchains is an advantage - as is using AI tools like GitHub Copilot or Claude Code in your daily workflow.
• Experience with React, TypeScript, and modern observability stacks such as OpenTelemetry, Prometheus, or Sentry rounds out your profile.
• You communicate confidently in English and, ideally, in German, and enjoy working in an international, technology-driven environment.
• You are willing to participate in an on-call rotation and occasionally travel for team workshops.

Why us?

• Meaningful Work: Help shape the story of one of Europe’s most exciting AI infrastructure companies from the ground up and contribute to strengthening Europe’s technological independence in the field of AI.
• High Level of Ownership: Work with direct access to the C-level team and actively shape the technical foundation of our platform. You will make decisions with real impact on scalability, reliability, and the developer experience across our teams.
• Strong Team: Become part of a growing, highly motivated tech team and collaborate closely with experienced engineers and technical leaders.
• Remote-First Work Model: Work in a way that helps you truly balance your professional, family, and personal life.
• Thoughtful Onboarding: Look forward to a structured onboarding plan, a welcome package with company merchandise, and your preferred hardware (MacBook Pro or ThinkPad).
• Room for Growth: Actively shape your role and develop it in directions that match your strengths and interests, whether in platform architecture, cloud infrastructure, reliability engineering, or developer experience.
• Attractive Benefits: Enjoy a wide range of employee offers and exclusive discounts with numerous brands and providers, JobRad bike leasing, contributions to your company pension plan and Germany Ticket, as well as the opportunity to work temporarily from other EU countries. And because we are a fast-growing scale-up, we continuously expand and improve our benefits offering.