Full Stack Engineer – Knowledge Graph Agentic AI

K&K Talents is an international recruitment agency that has been providing technical resources in the European region since 1993. This position is with one of our clients in Spain, which is actively hiring candidates to expand its team.

Title: Full Stack Engineer – Knowledge Graph & Agentic AI

Location: Barcelona, Spain (2 days onsite/week)

Employment Type: Contract

Role:

We are looking for a Full Stack Engineer – Knowledge Graph & Agentic AI to join an exciting project. The role focuses on building scalable data and AI platforms, combining Semantic Knowledge Graphs, RAG architecture, APIs, MCP endpoints, vector databases and Agentic AI.

You will work closely with data scientists, ontologists, architects, product managers and business stakeholders to deliver secure, scalable and high-quality data products for AI and analytics use cases.

Responsibilities:

• Build and maintain Semantic Knowledge Graphs using AWS Neptune.
• Develop RAG and Agentic AI solutions using Knowledge Graphs and vector databases.
• Build MCP endpoints and APIs for AI use cases.
• Develop data integrations and pipelines using modern cloud data technologies.
• Integrate solutions with MuleSoft, SLMs and LLMs.
• Optimize integration and API performance.
• Work with technical and business stakeholders in an Agile environment.

Required Skills:

• 5–10 years of relevant experience in Data Engineering, AI Engineering or Software Engineering.
• Proven experience delivering Semantic Knowledge Graph solutions.
• Strong hands-on experience with Knowledge Graphs - AWS Neptune, RDF, SPARQL.
• Experience with integration and API performance optimization.
• Hands-on experience with MCP endpoints/tools.
• Strong experience with MuleSoft APIs.
• Experience with SLM/LLM integration and fine-tuning.
• Experience with RAG, vector databases and Agentic AI.
• Strong skills in Python, React and SQL.
• Experience with Snowflake, dbt and Fivetran.
• Good knowledge of AWS, including AWS Bedrock.

Preferred Skills:

• Experience with Collibra and Immuta.
• Experience with complex enterprise Knowledge Graph environments.
• Masters degree in Computer Science, Data Management or a related field.
• Strong stakeholder management, documentation and cross-cultural collaboration skills.

Note: Applicants for employment in Spain should possess work authorisation, which does not require sponsorship by the employer for a visa.