Senior AI Engineer - Legal AI & LLM Pipelines

Lexroom Srl; Bellprat; Hybrid; EUR 70,000 - 100,000; Full time

Benefits offered by this job

Hybrid Work – Barcelona office

Health Coverage

Meal Vouchers

Performance Bonuses

Team Retreats & Off-sites

Job summary

Lexroom.ai in Barcelona is building the next generation of AI for legal work. You’ll design and deploy agent-driven and RAG-based AI systems to solve complex tasks with precision. You’ll tune LLMs, develop search pipelines, and collaborate with legal experts to elevate our platform.

Join a fast‑paced team with hybrid work, equity, and a salary range of €70,000–€100,000. You’ll grow with experts in ML, NLP, and production backends, shaping a product that redefines how legal professionals work.

Qualifications

• Proven expertise in building and managing robust ML pipelines.
• Strong Python skills with hands-on experience in LLM research and deep learning systems.
• Knowledge of search technologies such as full-text search, vector databases, or other large-scale retrieval systems.
• Collaborative mindset and readiness to work with legal experts, researchers, and engineers to keep improving the product.
• Familiarity with MLOps and integrating ML models into production backends (a strong plus).
• Up-to-date with LLM innovation, ideally with experience in pre-training or deploying large-scale models in real-world scenarios.
• Fluency in English, knowledge of Italian is a plus.

Responsibilities

• Design and build agent-driven and RAG-based AI systems to solve complex legal tasks with precision and efficiency.
• Fine-tune and post-train LLMs using cutting-edge supervised and reinforcement learning techniques to raise response quality.
• Develop and optimize large-scale search pipelines for LLM-powered agents.
• Implement and refine NLP algorithms to extract, structure, and validate information from legal documents.
• Run end-to-end evaluations to pinpoint bottlenecks, measure performance, and guide continuous improvements.
• Work closely with legal experts to design evaluation protocols and build reliable, domain-specific datasets that strengthen every layer of the stack.
• Maintain technical excellence by following established best practices, coding standards, and rigorous code-review processes.

Skills

ML pipelines

Python

Search technologies

Collaboration

MLOps

LLM innovation

English fluency

Job description

Lexroom.ai in Barcelona is building the next generation of AI for legal work. You’ll design and deploy agent-driven and RAG-based AI systems to solve complex tasks with precision. You’ll tune LLMs, develop search pipelines, and collaborate with legal experts to elevate our platform.

Join a fast‑paced team with hybrid work, equity, and a salary range of €70,000–€100,000. You’ll grow with experts in ML, NLP, and production backends, shaping a product that redefines how legal professionals work.