Senior Software Engineer (Python) (m/f/d)

About the role You will work in an agile, cross-functional engineering team behind one of the most innovative products we have: our Voice & Message Bot, built with agentic AI, catering for one of the most valuable customer use cases. You will ensure its infrastructure and architecture help customer conversations feel natural, enable the bot to be versatile and helpful, and remain reliable and cost-efficient. Your mission You design, build and evolve reliable backend systems and APIs in Python, making architecture and implementation choices that stand up to real-world complexity You take technical ownership end to end: you clarify the problem, identify risks and dependencies, choose pragmatic solutions, and remain accountable for quality in production You work across different parts of the system, integrations, data flows and infrastructure, and understand how technical decisions affect the rest of the product You raise the engineering standard through thoughtful code reviews, testing, observability, maintainability, and constructive technical discussions You work closely with a Product Manager and fellow engineers, challenge assumptions constructively, and connect technical decisions to customer and business outcomes You mentor other engineers, share knowledge, and help the team grow by enabling them to do their best work Your focus is backend engineering. You are comfortable making smaller frontend changes when needed Your profile You have senior-level experience building complex software and owning technical decisions end to end Python is one of your strongest technologies, and you are confident designing and maintaining backend services and APIs You have hands-on experience with AWS and Kubernetes, and are comfortable working with Docker You are a power user of agentic software development tools (ideally, have experience with Claude Code and/or GitHub Copilot), and you know how to boost your productivity with them safely and responsibly You care about code quality and write well-tested, maintainable software. You communicate technical decisions clearly, collaborate effectively and contribute to constructive discussions You have experience mentoring engineers through code reviews, onboarding or knowledge sharing Hands-on experience with agentic frameworks like LangChain is a big plus. Experience with Flask, MongoDB, React, TypeScript, or Node. js is a plus, but not required You have very good spoken and written English skills (C1 or above) Good spoken and written German skills (B1 or above) are a big plus Conditions & Benefits An open-minded and friendly team working with agile methods - as proven by our Kununu Score of 4,6 Flexible & hybrid working 60 days of workation per year in the EU Company events & sports offers Corporate benefits Company pension scheme Childcare allowance EGYM Wellpass membership discount Diverse development opportunities and a continuing education budget Position to be filled from You want to be part of our success story? Are you a team player looking for an opportunity to grow in an international and agile environment? Then join our team! Apply now and tell our Senio Recruiting Manager Marie why you are the right person for this job. We are looking forward to your application with CV, earliest start date and salary expectation. Please send your application documents in English. Want to get a comprehensive look behind the scenes at casavi? Follow us on Instagram @casavipeople and find out how team life is like at casavi!