Full Stack Developer

At IONOS, the leading European provider of cloud infrastructure, cloud services and hosting services, you will work together with a wide range of teams. We are characterized by open structures, a friendly working culture and flat hierarchies with a strong team spirit. We firmly believe that work and fun are compatible, and offer you the right environment for this. Our constant growth means that we are always looking for new colleagues. Become part of IONOS and grow with us.

We're launching a brand‑new AI Agent platform that will become the digital‑assistant of choice for small‑ and‑medium‑businesses (SMBs). This platform will feature various intelligent, autonomous agents handling tasks from customer interactions, like reservations and support, to strategic initiatives like marketing campaigns and sales. You'll be instrumental in developing the core application that enables these agents to operate, learn, and collaborate, ultimately driving significant value for our customers. This is a chance to work with cutting-edge web and AI technologies in a fast-paced, highly motivated environment.

As a Full Stack Developer, you will be responsible for bringing our vision to life across the entire application stack. Your core activities will include:

• Designing and Building the Intuitive Frontend: Create a seamless and responsive user experience for our SMB customers and their employees, ensuring the user interface is engaging and effective.
• Developing Robust Backend Services: Manage agent interactions, data storage, and the complex logic of agent-to-agent collaboration, ensuring reliability and scalability.
• Integrating State-of-the-Art AI APIs: Empower the digital workforce by leveraging APIs from leaders like OpenAI, Anthropic, Google, and Microsoft, enhancing functionality and innovation.
• Implementing Human-in-the-Loop (HITL) Checks: Ensure autonomous agent actions are safe, transparent, and auditable, maintaining user trust and engagement.
• Establishing Reliable Learning Systems: Develop systems for agents to learn from and store customer-specific information for contextually relevant future use.
• Collaborating with the Product Architect: Define technical specifications, estimate work, and deliver features efficiently within an Agile framework.
• Applying Cloud-Native Development Practices: Ensure the application is scalable, resilient, and efficiently deployed using cloud-native technologies.
• Participating in Code Reviews: Contribute to system architecture discussions and maintain high standards of code quality and documentation.

• Between 3-5 years of experience in Technology and Software companies, FinTech and E-Commerce, or any related field. Prior exposure to Cloud Services and SaaS and Artificial Intelligence and Automation advantageous plus.
• Proven Experience as a Full Stack Developer: Demonstrated success in shipping and maintaining cloud-native applications, showcasing expertise in both frontend and backend development.
• Deep Familiarity with Modern Web UI Development Frameworks: Proficiency in React, , or Angular, ensuring functional and aesthetic interfaces.
• Strong Proficiency with Modern Frontend and Backend Frameworks: Experience with , Python/Django/Flask, Spring Boot, or similar technologies.
• Solid Understanding of Modern AI Trends: Knowledge of agentic design patterns and multi-agent system architectures.
• Hands-On Experience with AI APIs: Integration experience with APIs from OpenAI, Anthropic, and other leading AI frameworks.
• Familiarity with Cloud-Native Practices: Competence in microservices, containers/Docker, Kubernetes, and CI/CD processes.
• Experience with Agile Development: Comfort and success working in fast-moving, iterative development cycles.
• Excellent Problem-Solving Skills: Strong communication abilities and a collaborative mindset, dedicated to team success and innovation.

• Hybrid working model.
• Flexible working hours through trust-based working hours.
• At some locations a subsidized canteen and various free drinks.
• Modern office space with very good transport connections.
• Various employee discounts for activities and products.
• Employee events such as summer and winter parties, as well as workshops.
• Numerous training and development opportunities.
• Various health offers, such as sports and health courses.

IONOS is the leading European digitalization partner for small and medium-sized businesses (SMB). The company serves around six million customers and operates across 18 markets in Europe and North America, with its services being accessible worldwide. With its Web Presence & Productivity portfolio, IONOS acts as a 'one-stop shop' for all digitalization needs: from domains and web hosting to classic website builders and do-it-yourself solutions, from e-commerce to online marketing tools. In addition, the company offers Cloud Solutions to enterprises who are looking to move to the cloud as their businesses evolve. 

We value diversity and welcome all applications - regardless of, for example, gender, nationality, ethnic or social origin, religion, disability, age as well as sexual orientation and identity, physical characteristics, marital status or any other irrelevant factor subject to applicable law.