Senior Full-stack Python Engineer (m/f/d) - Network Planning

Flix; Berlin; Hybrid; EUR 90.000 - 120.000; Vollzeit

Benefits dieser Stelle

Travel perks: 12 free Flix vouchers +

Hybrid work model

Wellbeing support

Learning & Development

Mentoring Program

Zusammenfassung

Flix is seeking a Senior Full-stack Python Engineer to own the backend APIs, data pipelines, and domain models for our network optimization platform. You will collaborate with OR Engineers to integrate optimization algorithms and build AI-enabled features that improve scheduling for vehicles, drivers, and timetables.

The role emphasizes hexagonal architecture, Kubernetes-based infrastructure, and a modern tech stack including Python, Flask, React, PostgreSQL, Kafka, and AWS.

Qualifikationen

• 5+ years of backend software engineering with Python.
• Experience with hexagonal/DDD architecture or ports-and-adapters design.

Aufgaben

• Own and evolve the backend: APIs, use case layer, domain models, serialization, and event-driven pipelines (Kafka).
• Take ownership of new product modules — design architectural scaffolds and ensure clean boundaries.
• Build and maintain infrastructure: Kubernetes deployments, CI/CD pipelines, and AWS resources.
• Collaborate with OR Engineers to integrate optimization algorithms into the product and enable AI capabilities.
• Work in an AI-augmented workflow using code agents and AI assistants to ship software.
• Contribute to architecture decisions, uphold code quality, and perform thorough testing.
• Write well-tested, self-documenting code following hexagonal architecture patterns.
• Share expertise and mentor colleagues to promote knowledge sharing.

Kenntnisse

Python

Backend engineering

CI/CD

Code reviews

AI-augmented development

Ausbildung

Bachelor's degree in Computer Science

Tools

Flask

React

PostgreSQL

Kafka

Docker

Kubernetes

Terraform

AWS

GitLab

Jobbeschreibung

At Flix, we offer a tech-driven environment where innovation meets real-world impact, with competitive pay, strong growth opportunities, and a culture of collaboration and ownership.

We're looking for an experienced Senior Full-stack Python Engineer (m/f/d) to join our Supply Division. You'll make an impact by taking ownership of core backend systems that power our network planning optimization product. Your work will directly support network planners in scheduling vehicles, drivers, and timetables — improving travel experiences for millions of passengers while driving profitability.

Our team builds and maintains an optimization platform addressing use cases from vehicle and driver scheduling to timetable optimization. We follow modern system design — Domain-Driven Design, Hexagonal Architecture, and SOLID principles — with strict architectural boundaries enforced by tooling. Our backend workloads (APIs, event consumers, Kubernetes jobs) are built to scale with high code quality standards.

The product's algorithm engine is developed by Operations Research Engineers using mathematical optimization. As a Senior Python Engineer, you will own the engineering shell around these algorithms: the APIs, use cases, data pipelines, infrastructure, and the domain models that connect optimization output to the rest of the system.

You'll collaborate closely with other engineering teams to design and implement the interfaces and contracts that connect our platform to the wider system landscape.

We're building AI into the product itself — combining LLMs with our optimization engine to solve planning problems in new ways.

Our current tech stack and toolset include:

• Python, TypeScript, Shell scripting
• Flask, React, Pytest
• PostgreSQL, Confluent Kafka, DataDog
• AWS tools, Terraform
• GitLab, Kubernetes, Docker, Azure AD

About the Role

• Own and evolve the backend: APIs, use case layer, domain models, serialization, and event-driven pipelines (Kafka)
• Take engineering ownership of new product modules — designing the architectural scaffold, wiring layers, and ensuring clean boundaries
• Build and maintain infrastructure: Kubernetes deployments, CI/CD pipelines, and cloud resources (AWS)
• Collaborate closely with Operations Research Engineers to integrate optimization algorithms into the productBuild AI capabilities into the product by combining LLMs with our optimization engine
• Work in an AI-augmented development workflow — actively using code agents and AI assistants as a natural part of how you ship software
• Contribute to architecture decisions and uphold code quality through reviews, testing, and continuous improvement
• Write well-tested, self-documenting code following hexagonal architecture patterns
• Share your expertise and mentor colleagues, promoting a culture of knowledge sharing and learning

About You

• Academic background in Computer Science or equivalent
• 5+ years of experience in backend software engineering with Python
• Experience with modern front-end stack (some basic front-end tasks are part of our scope)
• Experience applying clean architecture principles (hexagonal, ports-and-adapters, DDD) or similar approaches in production — able to contribute from day one
• Experience with relational databases (PostgreSQL) and event-driven systems (Kafka or similar)
• Strong experience in AI-augmented development — actively using code agents or AI assistants in daily work
• Solid experience with containerization (Docker, Kubernetes) and CI/CD pipelines
• Familiar with testing best practices: unit, integration, acceptance testing
• Experience with cloud platforms (AWS or similar) and infrastructure as code (Terraform)
• Familiarity with mathematical optimization or data-intensive applications is a plus

What We Offer

• Travel perks : 12 free Flix vouchers + 12 discount vouchers for friends & family.
• Work from (M)Anywhere : Depending on your role, work from another location for up to 60 days per year.
• Hybrid work model : We are an office-first company, but we offer flexibility to balance work and life.
• Wellbeing support : Access confidential 1:1 counselling, courses, and stress management for yourself and up to four family members.
• Learning & Development : Take advantage of language classes, training courses, and expert-led sessions to grow your skills.
• Mentoring Program : Connect with experienced colleagues to gain insights and accelerate your career.

To view more local benefits specific to each office location, please check out this link: Locations - Flix Career

Why Join Flix?

At Flix, we empower our teams to push boundaries and shape the future of mobility. As we continue to scale globally, we harness cutting-edge …

We recognize that everyone carries a unique set of valuable skills and experiences. If you think you could have an impact even though you don't meet 100% of the requirements, we still encourage you to apply.