Senior Backend Software Engineer

About the company: KIEFER is building Greece's integrated AI ecosystem. From renewable energy infrastructure and AI systems to robotics and enterprise applications, we connect the technologies that power Europe's intelligent future. Founded in 2014, KIEFER has delivered 600MW+ of energy projects and is now developing sovereign AI infrastructure, enterprise AI products and physical AI systems for Greece and Southeast Europe. About the role: We are looking for a Senior Software Engineer with strong backend expertise to join the team behind Sophea Meet, our AI-powered meeting assistant. Sophea Meet joins online meetings, records and transcribes conversations in real time, translates across languages, and turns discussions into clear action items and owners. Your primary focus will be backend development, but you will own features end to end and contribute to the frontend when needed. You will work closely with a product manager and UI/UX designer, helping shape features from the initial idea through release and production. Our Sophea Meet stack includes TypeScript and Node.js services running on Kubernetes, React and React Native on the client side, and PostgreSQL, Redis, and AWS across the platform. Python is also used across the wider Sophea ecosystem. What you will do: Build and own Sophea Meet features end to end, with a primary focus on backend development. Design and evolve TypeScript and Node.js services, APIs, and data flows. Contribute to React and React Native interfaces when required to complete a feature. Turn product goals into practical technical solutions, define scope, and make clear trade-offs. Build automated test coverage, monitoring, and reliable production services. Work closely with Product, Design, QA, DevOps, and Security to deliver secure and production-ready features. Use AI coding agents in development workflows while critically reviewing and validating their output. What you will need: 6+ years of professional software engineering experience, with backend development as your core expertise. Strong backend engineering experience with Python, together with hands-on experience building production services using TypeScript and Node.js. You should also be able to contribute to React interfaces when needed. Solid PostgreSQL knowledge and experience with event-driven systems and caching, including Redis or similar technologies. Experience building and operating distributed systems in production using Docker, Kubernetes, and AWS. Strong test automation skills, including choosing the right testing level and identifying flaky tests. Practical experience using AI coding agents beyond autocomplete, with the ability to critically review their output. High autonomy, sound product and architectural judgment, and strong communication skills. You can scope work, make pragmatic decisions, and collaborate effectively across teams. Nice to have: Experience with real-time systems, WebRTC, WebSockets, media pipelines, speech recognition, or translation. Experience with AI or LLM-powered products and technologies such as OpenSearch/Elasticsearch. Experience shipping products under regulatory or certification requirements such as GDPR, DORA, NIS2, SOC 2, or CASA. What is there for you Fully remote within the EU, or hybrid from Athens. No relocation expected. 28 weekdays of paid annual leave in Greece. Compensation benchmarked against the Greek and EU market, plus private health insurance or the remote-EU equivalent. Ownership of product features from day one, with dedicated QA, DevOps, and Security specialists available to support you. Daily work with LLMs, agent workflows, and AI infrastructure. Budget for conferences, courses, and certifications. Compensation Range: €60K - €90K