Python Senior Software Engineer

The Finanzen.net Group is a fintech company that supports retail and professional investors in making investment decisions through three core brands:
finanzen.net (the leading financial portal in the DACH region)
finanzen.net ZERO (broker)
TraderFox (tools for professional investors)
Since early 2025, the Group has been part of Inflexion, a European private equity firm that is strategically bringing together the previously independent business units. This realignment, combined with the Group’s strong innovative capabilities, creates new growth opportunities to further strengthen its position as a leading investment platform.
To execute this growth strategy, we are looking for motivated talents who want to actively shape this transformation.
Flexibility meets team spirit. Several times a year, we meet in person in Karlsruhe for workshops, team events, and more.
Job Description

We’re building a product that helps investors make better decisions by combining real-time market data, news and GenAI into a product used daily by investors.
We’re looking for a Senior AI Software Engineer with strong Python and AWS experience who enjoys taking ownership and shipping products end-to-end. You’ll work primarily with Python, FastAPI, GenAI and AWS , building scalable backend services, AI-powered features and data pipelines. You'll make real architectural decisions, like knowing when an LLM beats a well-tuned ML model or a simple heuristic, and own features from idea through production. We move fast, keep things pragmatic and give engineers a lot of ownership. Responsibilities
Build and ship AI-powered, full-stack products from idea to production.
Develop scalable backend services with Python & FastAPI.
Design, deploy and operate production systems on AWS.
Drive architecture and technical decisions and contribute to code reviews.
Build practical GenAI solutions and evaluate where LLMs actually add value.
Use AI coding tools such as Claude or Codex to improve development workflows.
Own reliability, observability and performance of what you build.
Qualifications

Senior-level Software Engineering experience with a strong track record of shipping production software.
Practical experience with GenAI and AI-assisted development.
Experience in a startup, scale-up or similarly fast-moving environment.
Strong end-to-end ownership: you take problems from architecture → code → deployment → production.
Pragmatic engineering mindset: build simple solutions, ship fast, iterate.
Strong communication skills and the ability to make independent technical decisions.
Strong Python skills — Python is central to this role.
Hands-on AWS experience or similar cloud provider — this is essential.
Experience with FastAPI, cloud architecture and production systems.
Nice to Have
Terraform / Other Infrastructure as Code
TypeScript / Angular / React
Microservices & data pipelines
Experience with finance, markets, trading or investment products

Additional Information

With us, you’ll find a modern work environment with over 250 colleagues, characterized by trust, flexibility, and genuine collaboration. In addition to our offices in Karlsruhe and Berlin, our Munich location is also available to you —supplemented by up to 15 days of “workation” within the EU per calendar year.
We actively support your personal and professional development through training, seminars, and conferences in a dynamic fintech and stock/finance environment. We place great value on open communication, team spirit, and shared success.
You can also expect the following benefits:
Modern office hubs
Professional development opportunities in the financial markets and investment sectors
Regular team events & a strong company culture
Health and mobility benefits (Jobrad, public transportation subsidy)
Attractive financial benefits & other perks
An environment where you can contribute, grow, and feel at home.