Junior Full Stack Developer (m/w/d) Individualreisen

About the Role

At CHECK24, we are shaping the future of digital comparison platforms, aiming to provide our customers with Germany's best, simplest, fairest, and most transparent comparison experience. We are developing the next generation of tailored travel booking solutions: an AI-powered travel planner that supports customers from inspiration right through to final booking via chat, covering flights, hotels, holiday homes, and more in a seamless workflow with real-time bookings.

If you are passionate about digital products, enjoy working with cutting-edge technology to deliver real customer value, have a keen interest in how generative AI functions, and enjoy programming yourself, join our dynamic team. You will experience a unique working atmosphere with flat hierarchies, short decision-making paths, and a modern tech culture.

Responsibilities

• Work on diverse and innovative projects related to product comparison, including booking flows, comparison results, self-service features, and AI-assisted assistants. Responsibilities span from backend data logic to frontend user interfaces.
• Participate in full-stack software development, enhancing systems end-to-end: APIs, backend services, LLM services and orchestration, and performant, user-friendly frontend components.
• Develop intelligent features utilizing Large Language Models (LLMs) such as chat and assistant functions, information extraction and structuring, and data-driven recommendations. Work with LLM agents and orchestrate their usage involving tools, state/memory management, and workflows to ensure productive and controllable AI integration.
• Own and drive technical implementation of product improvements independently, maintain clean code, and ensure stability and future readiness of applications.
• Ensure quality assurance through strict typing, static analysis, and automated unit, integration, and end-to-end testing; advance our testing infrastructure continuously.
• Collaborate closely with the product management team to introduce new features, contribute ideas, and help optimize development processes.

Requirements

• Successful completion of a vocational training as an IT specialist or a relevant degree in a related field.
• Full-stack mindset with initial experience in full-stack web development; understanding of modern API development (e.g., type-safe APIs) and clear data and interface modeling. Eagerness to understand and implement features end-to-end across service and language boundaries.
• Interest in AI features involving Large Language Models and initial exposure to agent-based workflows.
• Proficiency in AI-assisted development: confident use of AI-driven tools such as LLMs and coding agents, familiarity with relevant patterns including specification-driven development, persistent agent instructions, and iterative agent loops, along with solid programming skills.
• Quality-conscious, solution-focused, and independent working style complemented by self-motivation and enthusiasm for continuous learning and evaluating emerging trends. Driven to consistently advance the product, team, and personal skills.
• Fluent German and good command of English language skills.

Benefits

• Attractive salary package plus vouchers for CHECK24 products and subsidized company pension schemes.
• Flexible work arrangement: option to work full time in the office or remotely on Fridays; up to two weeks of workation annually.
• Personal growth support via targeted training, regular feedback, and an individual budget dedicated to continuing education.
• Excellent equipment from day one, including a MacBook, additional monitors, ergonomic workstation, and optional further hardware.
• Comfortable work environment with free lunch, beverages, fruit, muesli, monthly team lunches, 50% subsidy for the EGYM Wellpass fitness program, and weekly personal training sessions.
• Convenient travel: centrally located office near Kö-/Rheinufer by Heinrich-Heine-Allee, with coverage of the Germany ticket and subsidized job bike/e-bike options for sustainable commuting.
• Strong team culture with numerous events, summer and Christmas parties, sports activities, and a dedicated annual budget to support team events.