Senior Python Developer (m/w/d) FastAPI, SQLAlchemy & OAuth2/OIDC - remote & Berlin/FFM

Für unseren Kunden suchen wir ab 01/2026 einen Senior Python Developer (m/w/d) FastAPI, SQLAlchemy & OAuth2/OIDC für den voraussichtlichen Zeitraum bis 06/2026 mit der Option auf Verlängerung. In diesem großen Greenfield-Projekt kann unter Nutzung moderner Technologien ein Beitrag zur Energiewende geleistet werden. Das Projekt ist als Vollzeitbeschäftigung geplant. Mindestens 3 Tage pro Monat finden vor Ort in Frankfurt am Main oder Berlin statt.

Hinweis: Bitte sehen Sie von Bewerbungen ab, die nicht alle Mindestkriterien erfüllen.

Project Description:
The team is building an internal platform for software product developers to accelerate the development and delivery of software products to tackle the massive challenges facing the energy sector. The Platform is a service oriented, cloud-native platform that is being built to provide application teams with self-service capabilities to develop, run and operate their software products. The Platform provides services for application infrastructure, data, service lifecycle management, application build and delivery as well as services to operate their software products. The platform is deployed as a hybrid cloud, encompassing both private cloud and selected public clouds.

Targets in that Position:
- Objective: Programming
> Writing production grade source code to implement architecture design specifications
> Writing unit tests and providing code documentation
> Actively participating in engineering team activities such as agile ceremonies
Objective: Technical Leadership
> Making technical decisions withing the boundaries set by the architecture design
> Communication of decisions to peers, architects and relevant stakeholders
> Generate and communicate status reports to lead architects and delivery leads
> Facilitation of meetings and presentation of technical concepts in simple terms to medium sized audiences.
- Objective: General Leadership
> Providing guidance to other developers in the team
> Ensuring on-time delivery of application features and/or entire software components
- Objective: Continuous improvement
> Identifying opportunities for improvements towards the development process
> Promoting and fostering agile ways of working

Must have:
- 8+ years of experience in professional Software Development using High-Level programming languages
- Advanced Python (3.9+) proficiency. Strong command of asynchronous programming (asyncio, aiohttp, etc.), multiprocessing, and concurrency models
- Extensive experience with Python frameworks for building scalable APIs and services, specifically FastAPI
- Expertise in modular software design, with an emphasis on separation of concerns and maintainable codebases
- Strong grasp of type hinting, dependency injection, and automated testing frameworks (pytest, unittest, or equivalent)
- Experience working with multiple database paradigms: Relational (PostgreSQL), NoSQL (Redis, MongoDB, ArangoDB/Neo4J). Experience with database libraries like SQLAlchemy.
- Deep understanding of microservice design principles, including service boundaries, state management, and inter-service communication (REST, gRPC, or message queues) and API design.
- Thorough understanding of application and API security principles and related frameworks and technologies OAuth2, OIDC.

Nice to have:
- Proficient in database integration for microservices —able to design schema and data models per service and manage data consistency and performance
- Hands-on experience with containerizing services