Senior Software Engineer (m/f/d)

www.polarise.eu; Düsseldorf; Remote; EUR 70,000 - 100,000; Full time

Benefits offered by this job

Remote-first work model

Structured onboarding and welcome pack

Hardware (MacBook Pro or ThinkPad)

Job summary

POLARISE is looking for an experienced backend engineer to develop and operate core services for its Sovereign AI Cloud. You will contribute to authentication, multi-tenancy, and secure, scalable platform components using Python, FastAPI, PostgreSQL, and Redis.

You will design REST APIs, implement OpenAPI specs, and work with modern tools like Kubernetes, GitOps, and observability stacks. English is essential; German is a plus. Join a cross-functional, international team with remote-first policy.

Qualifications

• Several years of backend development experience with at least one modern language; hands-on Python, FastAPI, Pydantic, and SQLAlchemy preferred.
• Strong experience designing and developing REST APIs and OpenAPI specifications.
• Proficient with relational databases (PostgreSQL) and in-memory stores (Redis).
• Familiarity with OAuth2, OIDC, JWT, RBAC; Keycloak is a plus.
• Clean, maintainable, well-tested code; experience with pytest, mypy, and ruff.
• Practical experience with Git, Docker, and CI/CD pipelines; Kubernetes experience a plus.
• Knowledge of GitOps approaches and tools (Helm, ArgoCD); exposure to AI toolchains is nice.
• English communication skills; German ideally; ready for international environment and occasional travel.

Responsibilities

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

Skills

Python

FastAPI

Pydantic

SQLAlchemy

REST APIs

PostgreSQL

Redis

OAuth2

JWT

RBAC

Keycloak

pytest

mypy

ruff

Git

Docker

CI/CD

Kubernetes

GitOps

Helm

ArgoCD

OpenAI

React

TypeScript

OpenTelemetry

Prometheus

Sentry

English

German

LLM integrations

Tools

PostgreSQL

Redis

OpenAPI

Keycloak

Git

Docker

CI/CD tooling

Kubernetes

Helm

ArgoCD

OpenTelemetry

Prometheus

Sentry

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.
• 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.