Senior Java & LLM Engineer

Wizeline; Barcelona; Presencial; EUR 65.000 - 90.000; Jornada completa

Ventajas ofrecidas por este puesto de trabajo

Commitment to Professional Development

Flexible and Collaborative Culture

Total Rewards

Descripción de la vacante

Wizeline is seeking a Java Developer to design, build, and scale backend services in a modern AI-powered platform. You’ll work with Java 17+, Spring Boot, and microservices, accelerating AI features for an enterprise-grade product.

You will integrate LLM providers, vector stores, and RAG pipelines, collaborating with product, frontend, and DevOps teams to deliver robust, testable software and reliable backends.

Formación

• 7 years of hands-on software development experience with Java 17+.
• Strong experience with Spring Boot, REST API design, and microservice architectures.
• Experience with PostgreSQL, MySQL, and ORM tools like Hibernate/JPA.
• Familiarity with containerization Docker and modern CI/CD workflows.
• Understanding of core LLM concepts and REST-based AI APIs (OpenAI, Anthropic).
• Familiarity with LangChain4j or Spring AI or similar Java AI frameworks.
• Basic understanding of RAG (Retrieval-Augmented Generation) and vector stores.

Responsabilidades

• Design, build, and maintain scalable RESTful APIs and microservices using Java and Spring Boot.
• Connect backend systems with modern LLM provider APIs using Java AI libraries like LangChain4j or Spring AI.
• Assist in integrating vector databases (pgvector, Qdrant, Pinecone, Milvus) to support intelligent search and knowledge retrieval.
• Write clean, testable code (JUnit/Mockito) and collaborate with product managers, frontend engineers, and DevOps to ship AI-enhanced features.

Conocimientos

Java 17+

Spring Boot

REST API design

Microservices

JUnit/Mockito

PostgreSQL

MySQL

Hibernate/JPA

LangChain4j

Spring AI

OpenAI APIs

Herramientas

Docker

LangChain4j

Spring AI

Descripción del empleo

Wizeline, a global AI-native technology solutions provider, develops cutting-edge, AI-powered digital products and platforms. We partner with clients to leverage data and AI, accelerating market entry and driving business transformation. As a global community of innovators, we foster a culture of growth, collaboration, and impact.

With the right people and the right ideas, there’s no limit to what we can achieve.

Sounds awesome, right? Now, let's make sure you're a good fit for the role:

Key Responsibilities

About the Role

We are looking for a Java Developer with a foundation in core Java engineering and an eagerness to build modern, AI-powered applications. In this role, you will work on scaling backend microservices while leveraging emerging AI frameworks to integrate Large Language Models (LLMs), RAG (Retrieval-Augmented Generation) pipelines, and intelligent automation into our enterprise platform.

Key Responsibilities

• Backend Engineering: Design, build, and maintain scalable RESTful APIs and microservices using Java and Spring Boot.


• AI & LLM Integration: Connect backend systems with modern LLM provider APIs (OpenAI, Anthropic, Ollama, Hugging Face) using Java AI libraries like LangChain4j or Spring AI.


• Vector Search & RAG: Assist in integrating vector databases (e.g., pgvector, Qdrant, Pinecone, or Milvus) to support intelligent search and contextual knowledge retrieval.


• Collaboration & Testing: Write clean, testable code (JUnit/Mockito) and collaborate with product managers, frontend engineers, and DevOps to ship AI-enhanced features.

Qualifications & Skills

• 7 years of hands-on software development experience with Java 17+.


• Strong experience with Spring Boot, REST API design, and microservice architectures.


• Experience with relational databases (PostgreSQL, MySQL) and ORM tools (Hibernate/JPA).


• Familiarity with containerization (Docker) and modern CI/CD workflows.

Basic AI / LLM Knowledge:

• Understanding of core LLM concepts (prompts, context windows, tokens, embeddings, and temperature).


• Hands-on experience or coursework integrating REST-based AI APIs (e.g., OpenAI, Anthropic, Azure OpenAI).


• Familiarity with at least one Java AI framework (LangChain4j or Spring AI) or open-source vector stores.


• Basic understanding of RAG (Retrieval-Augmented Generation) architecture.

Nice-to-Haves

• Exposure to Python for prototyping or basic data processing.


• Experience with event-driven architectures (Apache Kafka, RabbitMQ).


• Experience deploying applications on cloud platforms (AWS, GCP, or Azure).

What we offer

• Commitment to Professional Development


• Flexible and Collaborative Culture


• Total Rewards

*Specific benefits are determined by employment type and location.