Senior Java Backend Developer – Agentic AI

Holycode is looking for a Senior Java Backend Developer with hands-on experience in agentic AI to join our team in Bucharest.

You will build reliable backend services and integrate AI capabilities into business applications. The role combines strong Java engineering with the ability to develop AI agents, connect them to business systems and make their behaviour observable and testable.

What awaits you:

• Design, develop and maintain backend applications using Java and Spring Boot.
• Build APIs and services that support business-critical workflows.
• Integrate LLMs and AI agents into applications, enabling them to retrieve information, use tools and interact with business systems.
• Develop agent workflows with clear permissions, validation and human approval where needed.
• Connect AI features to databases, APIs and relevant knowledge sources.
• Take ownership of backend quality, including testing, security, performance and maintainability.
• Implement monitoring and error handling for both conventional services and AI-powered workflows.
• Collaborate with product teams and engineers to translate business requirements into technical solutions.
• Use AI-assisted development tools thoughtfully, reviewing generated code and taking responsibility for its quality.
• Contribute to architecture discussions, code reviews and knowledge sharing.

What we expect from you:

• Several years of professional backend development experience with Java.
• Strong experience with Spring Boot and designing REST APIs.
• A solid understanding of relational databases, data modelling and transaction management.
• Experience building and maintaining production applications, including automated testing and troubleshooting.
• Hands-on experience integrating LLMs into applications and building agent workflows involving tool calling or external systems.
• An understanding of the limitations of AI systems and approaches to validation, retries, fallbacks and access control.
• Familiarity with Git, CI/CD and containerised applications.
• Strong analytical skills and a practical approach to technical decisions.
• Clear communication, a collaborative mindset and ownership of your work.
• High proficiency in written and spoken English.
• Availability to work onsite from our Bucharest office.

Bonus points for:

• Experience with Spring AI, LangChain4j or similar libraries.
• Familiarity with the Model Context Protocol (MCP).
• Experience with RAG, embeddings and vector databases.
• Experience with Kafka or other messaging technologies.
• Knowledge of distributed and event-driven systems.
• Experience with AWS, Azure or Google Cloud.
• Familiarity with Kubernetes and application observability.
• Working knowledge of Python or TypeScript.

Why you will love working here:

• Opportunities to combine established backend engineering with practical AI development.
• A welcoming working atmosphere in an open-minded multinational team.
• An office-based role in Bucharest, with close collaboration and knowledge sharing.
• All the necessary equipment to support your work.
• A budget for professional development, including courses, conferences and books.
• A flexible benefits budget.
• Premium private medical subscription with nationwide coverage.
• Skilled and experienced colleagues.
• Opportunities to build products that make a difference.
• Opportunities to learn and grow with us.

If you enjoy building reliable backend systems and want to apply agentic AI to real business workflows, please submit your CV in English.