Senior AI Engineer (BCN)

Lexroom

About Lexroom

• is building the AI platform where legal work gets done. In just over two years, we've grown from zero to €25M ARR, and today more than 20,000 legal professionals across
• Italy, Spain, Germany, France, and Bulgaria rely on Lexroom
• We're backed by $73M from Left Lane Capital, Base10 Partners, and Eurazeo, and we're a team of around 300 builders who move fast, say things straight, and own each outcome.
• Our next goal? Become Europe's most-used legal product.

Lexroom

• Lexroom, we leave buzzwords behind. Here, you’ll build something that lasts:
• a trusted platform, a strong reputation, a new standard for the legal world.
• An Exceptional Team.
• Lexroom.ai, you’ll work alongside top talent in tech and legal AI.
• Our focused teams operate with purpose and autonomy, so every contribution delivers visible results.
• You’ll collaborate with people who pair innovation with rigor, curiosity with discipline, ambition with depth.
• Growth that Matters.
• As we scale, your work will shape the future of legal technology and set new standards for the field.
• Impact is defined by vision and execution, not by age or title. If you’re ready to take responsibility, you’ll find real opportunities to grow and lead high-stakes projects.

Responsibilities

• Be part of the team setting the benchmark for legal AI in Europe.
• Collaborate with exceptional colleagues in a culture that values competence, curiosity, and ambition.
• Your contribution will directly influence how legal professionals work—faster, clearer, and more efficiently.
• 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.
• 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.

Requirements

• 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.
• and readiness to work with legal experts, researchers, and engineers to keep improving the product.

Familiarity with MLOps

• Up-to-date with LLM innovation, ideally with experience in pre-training or deploying large-scale models in real-world scenarios.
• Fluency in English, both written and spoken, knowledge of Italian is a plus.
• Lexroom.ai, ambition meets discipline and purpose.

Preferred

• and integrating ML models into production backends (a strong plus).

Pay

Rewarding Your Contribution.

Benefits

• We hire exceptional people to make a difference—and we give them space to lead.
• €70,000 – €100,000
• Align your growth with the company’s long-term success.
• Flexibility to balance remote work with in-person collaboration at our
• Comprehensive insurance to keep you secure and focused.
• Daily support for your lunch breaks.
• Rewards directly tied to measurable results.
• Dedicated time to connect, collaborate, and spark bold ideas.

We’re not just building a product—we’re setting a new standard for the legal world. If you’re ready to contribute to something lasting and meaningful, we’d love to hear from you.