Senior Fullstack Engineer & Hands-on Architect (Python / FastAPI) (m/f/d)

Deutz; Köln; Hybrid; EUR 90,000 - 130,000; Full time

Benefits offered by this job

30 Tage Urlaub

Remote Option

Weiterbildungsmöglichkeiten

Benefits von Anbietern (online und vor

In-house medizinische Versorgung

Kantine im Werk

Fahrradleasing

Deutschlandticket Rabatt

Gute ÖPNV & Parkplätze

Urban Sports Club Mitgliedschaft

Job summary

DEUTZ AG sucht eine erfahrene Senior Fullstack Engineer & Hands-on Architect, die Backend-lastige Features in FastAPI gestaltet und architektonisch verantwortet. Sie arbeiten eng mit Domänenexperten zusammen, definieren MVPs und gestalten robuste Schnittstellen zu Partnern.

Frontend-Verständnis ist wichtig, um UI-Integrationsaspekte zu verstehen. Ihre Aufgabe umfasst die Weiterentwicklung einer produktorientierten Architektur in einem zukunftsorientierten Umfeld, einschließlich

Qualifications

• Mehrere Jahre Produktion Softwareentwicklung.
• Starke Backend-Kompetenz in Python und FastAPI.
• Hands-on Architekt für produktnahe Services – nicht nur Folien.
• Hands-on Frontend-Erfahrung zur UI-Integration.
• Komplexe Geschäftslogik in sauberem, testbarem Code.
• Gute API-Design-Fähigkeiten (Verträge, Validierung, Versionierung).
• Datenorientierte Produkte mit Lebenszyklus-Statusverfolgung.
• Praktische Erfahrung mit KI-Coding-Agenten und deren Prüfung.
• Muster zur Microservices-Kollaboration und Integrationsaspekten.
• Arbeiten direkt mit Stakeholdern und Umsetzung konkreter Herzstücke des Domäneninputs.

Responsibilities

• Verantwortung für die technische Architektur: Domaingrenzen, Datenmodelle, Service-Cuts, ADRs.
• Design und Implementierung Backend-lastiger Features und APIs in FastAPI – Lifecycle und Datenverarbeitung, Marktplatz-ähnliche Abläufe, Partner- und Logistik-Integration.
• Mit Domänenexperten die Produktvision schärfen: Anforderungen hinterfragen, einfache Lösungen vorschlagen, MVP-Umfang definieren.
• Gestaltung robuster, gut dokumentierter Schnittstellen zu umliegenden Systemen und Partnern.
• Beschleunigung der Lieferung durch modulare Architektur und wiederverwendbare Komponenten.
• Stärkung von Qualitätspraktiken (Unit/Integration-Tests, Linting, Review-Standards).
• Zusammenarbeit mit QA, Product- und Platform-Teams an reibungslosen Release-Zyklen; Unterstützung von CI/CD aus Entwicklersicht.

Skills

Python

FastAPI

Frontend-Erfahrung

Architektur-Design

API-Design

Microservices

KI-Coding-Agenten

Unit/Integration Testing

Team-Zusammenarbeit

Job description

Senior Fullstack Engineer & Hands-on Architect (Python / FastAPI) (m/f/d)

Standort: Koln, HQ

Eintrittsdatum: Immediately

Arbeitszeit: Full-time

Befristung: Permanent

DEUTZ AG has evolved in recent years into a system provider of innovative and sustainable mobility and energy solutions. With around 6,000 employees worldwide and a global network of over 1,250 sales and service locations in more than 180 countries, we are actively shaping the transformation of mobility and energy supply. We continuously advance our technologies with a clear focus on market requirements, technological innovation, and social responsibility.
As a system provider, our portfolio today goes far beyond the traditional combustion engine: we offer high-performance drive systems for off-highway applications, alternative drive solutions as well as decentralized energy and power generation systems - wherever power, reliability, and adaptability are required. A comprehensive range of services completes our product portfolio, from maintenance and repair to spare parts trading, remanufacturing, and digital, data-based services.

We are building a suite of digital products in the circular economy and remanufacturing space - the lifecycle of engines and components, the processes around reconditioning, and the connected service and partner network.
This is a product role, not a ticket role: you work directly with domain experts, shape what gets built and how, own the architecture of the services behind it, and take features from idea to production. Backend is the center of gravity; fullstack experience is required to work with the frontend team and judge end-to-end feasibility.
We work agentic: AI coding agents are part of the daily toolchain. We expect you to use them to move fast and to review and steer their output with the same rigor you would apply to any production code.
Language: German is the primary project language, English fluent (business-level).

Responsibilities:

• Own the technical architecture: domain boundaries, data models, service cuts, integration patterns, ADRs
• Design and implement backend-heavy features and APIs in FastAPI - lifecycle and process data, matching and marketplace-style flows, partner and logistics integration
• Shape the product with domain experts: challenge requirements, propose simpler solutions, define MVP scope and what comes after
• Design resilient, well-documented interfaces to surrounding systems and external partners
• Raise delivery speed through modular architecture, reusable components and effective use of coding agents
• Strengthen quality practices (unit/integration testing, linting, formatting, review standards)
• Work with QA, product and platform teams on smooth release cycles; support CI/CD and deployment readiness from a developer perspective (no primary DevOps ownership)

Must-Haves:

• Several years of production software development
• Strong backend expertise in Python and FastAPI
• Hands-on architect for product-facing services - not architecture on slides
• Hands-on frontend experience to understand UI integration constraints
• Complex business logic in clean, testable, maintainable code
• Strong API design (contracts, validation, versioning, error semantics)
• Data-centric products: domain entities, lifecycle/state handling, traceability across process steps
• Practical experience working with AI coding agents and the judgment to review their output critically
• Microservice collaboration patterns and integration concerns
• Works directly with business stakeholders and turns vague domain input into a buildable increment

What we offer:

• Full-time
• 30 days of vacation per year
• Option to work remotely
• Extensive range of training and professional development opportunities
• Employee benefits from various providers, both online and in-store
• Comprehensive healthcare provision (e.g. flu and COVID-19 vaccinations, carotid artery screening) with our own in-house medical centre
• Staff canteen and kiosk on the worksite
• Bicycle leasing scheme and discounted Deutschlandticket
• Good public transport links, as well as free parking
• Discounted Urban Sports Club membership

Are you looking for a varied and exciting role in a supportive team, with attractive remuneration and ideal working conditions? If so, we look forward to getting to know you!

We welcome and support the diversity of our workforce and are convinced that it is one of the most important factors in our company's success. Diversity makes us more open-minded, innovative and competitive.