Senior Backend Engineer / Staff Engineer

Our client in the SaaS sector based in Vienna offers an exciting opportunity for experienced backend specialists who enjoy working with modern technologies and want to help shape scalable architectures. The position is at the level of a Staff Engineer - a technical expert who leads through expertise, but without personnel responsibility., * Development and continuous improvement of backend services using Python, Django, Django REST Framework and FastAPI, complemented by modern technologies such as Go, Java or NestJS.

• Active contribution to and further development of the system architecture by applying:

• Domain-Driven Design
• Modular Monoliths (Moduliths)
• Microservice principles
• Hexagonal Architecture

• Design and ongoing development of event-driven systems using asynchronous communication via RabbitMQ or Kafka.
• Responsibility for performance optimization through refactoring, SQL tuning in PostgreSQL, and ensuring performant APIs.
• Technical leadership through clean, tested, and well-documented code, code reviews, and active knowledge transfer within the team.
• Mentoring of junior and mid-level engineers in architectural decisions, code quality, and best practices - without disciplinary responsibility.
• Use of modern tools such as AI coding assistants and automation to increase efficiency.
• Close collaboration with product, frontend, and QA colleagues in an agile Scrum/Kanban setup.

• At least 10 years of experience in backend development, ideally with a focus on Python and Django.
• Alternatively or additionally: experience with Java, Go or Node.js/NestJS.
• Strong architectural skills and confident working with:

• Domain-Driven Design
• Modular Monoliths
• Microservices
• Hexagonal Architecture

• Hands-on experience with RabbitMQ or Kafka in production environments.
• Proven track record in developing and integrating REST-based APIs, ideally also with FastAPI.
• In-depth knowledge of PostgreSQL - from schema design to performance optimization.
• A DevOps mindset with experience in Docker and Kubernetes is a plus.
• Comfortable working in agile environments and excellent English skills; German is a plus.
• Motivation for continuous learning and openness to new technologies and working methods.