Fullstack Engineer

Düsseldorf | hybrid | permanent YOUR MISSION As a Senior Fullstack Engineer, you are a core builder in our Research and Development initiative: an AI platform that automates security reviews at the architecture level. You spend most of your time on the backend - building AI-integrated services, async pipelines, and the APIs that power our research platform. You also build the surfaces through which our consultants work with AI output, turning probabilistic results into something people can genuinely trust. YOUR ROLE - Backend & API: Build and extend FastAPI endpoints, Celery task orchestration, PostgreSQL schemas, and GCS object storage; clean integration with the AI/ML pipeline. - Data Flow Ownership: Design how the platform's data is stored, versioned, and served to the UI. - Knowledge Approval Workflow: Design and extend the lifecycle layer for documents in the platform: data model, SLA tracking, escalation signals, and provenance metadata. - Consultant-facing UI: Build the surfaces where AI output meets users: long running task UX, real time updates, and the path from polling to WebSocket/SSE streaming. - End-to-End Delivery: Work with the AI team and an external UX designer to ship features from pipeline to UI - and own what works under the hood. - Platform Reliability: Shape test strategies, structured logging, performance budgets, and the SDLC and agile practices the team needs as it grows. YOUR PROFILE Must haves - 5+ years of fullstack experience with production ownership of complex software - ideally including AI-integrated workflows - Python and FastAPI at senior level: API design, request validation with Pydantic, structured errorr handling - PostgresSQL: schema design, migrations, query optimizations, audit and versioning patterns - Async at scale: streaming responses (SSE/WebSocket), bounded concurrency, retry strategy across nested boundaries, idempotent task design with Celery or equivalent

• React and TypeScript: state management (TanStack Query, Zustand or similar), data-driven UI for domain experts - Production deployment: Docker, Kubernetes or equivalent, CI/CD, and observability tooling (Sentry, OpenTelemetry or similar) - Product judgement: you know what fits the roadmap and you speak up when something doesn't - Experience building SDLC and agile practices in a small team - Strong English communication A real plus - GCP experience: Cloud Run, GCS, Secret Manager, Vertex AI - Vector search (Weaviate, pgvector or similar) or graph databases (Neo4j or similar) - AI/LLM systems: eval frameworks, prompt versioning, regression on non-deterministic outputs - Security engineering: authn/authz patterns, session management, secrets handling - Test strategy: experience building testing practices systematically within a team - Background in developer tools, data-heavy SaaS, or expert-facing products WHY CLOUDYRION - We support EU Blue Card

sponsorship and offer a relocation package for international hires - 30 days of vacation plus additional days off on Christmas, New Year's Eve, and your birthday - Hybrid work with two remote days per week, trust-based working hours and the opportunity of Workations in any EU country - Individual learning and development opportunities, including full coverage of advanced trainings, certification costs, and educational leave for exam days - In-house gym, massage chairs, gaming area, and dedicated break spaces - Regular team events and plenty of space for real collaboration **ABOUT CLOUDYRION** CLOUDYRION was founded in 2020, bootstrapped and built around a simple idea: cybersecurity done properly, by people who actually care. We work with large enterprises in the telecoms, banking, insurance, automotive and critical infrastructure sectors. Our Secure by Design, Ethical Hacking and Secure Strategy Consulting services help them get security right from the ground up.