Senior AI Research Engineer in London

Clio is the global leader in legal AI technology, empowering legal professionals and law firms of every size to work smarter, faster, and more securely. We are transforming the legal experience for all by bettering the lives of legal professionals while increasing access to justice.

Clio signed a definitive agreement to acquire vLex in 2025. This transaction is a major milestone in Clio’s platform evolution and a turning point for the future of legal work. It combines Clio’s legal operating system, trusted by more than 400,000 legal professionals, with vLex’s cutting‑edge legal intelligence platform, which includes Vincent AI, built on the industry’s most comprehensive global legal database. Together, these platforms establish a new category of intelligent legal technology at the intersection of the business and practice of law, empowering legal professionals to seamlessly manage, research, and execute legal work within a unified system.

What you’ll work on:

• Foundations of retrieval at scale: Re‑think how we search over vast, heterogeneous legal corpora. Exploring new approaches to chunking, query augmentation, hybrid sparse/dense embeddings, contextual embeddings, quantisation, to push the boundaries of recall, speed, and efficiency.
• Learning to rank with legal signals: Experiment with re‑ranking strategies for search results that incorporate legal‑specific signals that go beyond keyword matches and semantic similarities, to surface the most authoritative and relevant results first.
• Agentic infrastructure for legal workflows: Develop the foundations of agents that can decompose complex legal tasks, plan across multiple tools, and execute with traceability and guardrails.
• Evaluation frameworks for retrieval and agents: Design and run experiments that help us measure system performance against the needs of legal professionals.
• Grounding and validation of model responses: Create mechanisms that ensure model responses are trustworthy by anchoring them in trusted legal sources.

A day in the life might look like:

• Leading complex research projects focused on LLMs, advanced information retrieval, and novel AI applications in the legal domain.
• Designing and implementing sophisticated prototypes that demonstrate the feasibility and business value of cutting‑edge research ideas.
• Driving the transition of research innovations from prototype to production, collaborating closely with product and engineering teams.
• Contributing to strategic research planning by identifying high‑impact research opportunities.
• Staying at the forefront of AI research, particularly in NLP, LLMs, and legal AI.
• Lead technical discussions and code reviews, ensuring high standards of research quality.
• Collaborating with cross‑functional stakeholders including product managers, legal engineers, and business leaders.
• Documenting and communicating research findings through internal presentations and technical documentation.
• Contributing to the development of research infrastructure and best practices.

What you may have:

• Masters degree or PhD in Computer Science, Machine Learning, Data Science, Artificial Intelligence, or a related field.
• Industry experience in applied AI research or engineering.
• At least one of the following experiences: Information retrieval systems, LLM fine‑tuning and evaluation, LLM hosting and inference optimization, LLM workflow automation.
• Track record of independently delivering complex technical projects from ideation to implementation.
• Hands‑on experience in working closely with product engineering in production applications.
• Proficiency in data manipulation, cleaning, and pre‑processing for complex unstructured data sets.
• A proven ability to quickly learn new technologies and adapt to a fast‑paced environment.
• A strong understanding of modern AI tools and approaches.
• Clear communication skills and the ability to build trust with both internal teams and external customers.
• A desire to continuously learn, challenge yourself, and refine your craft.
• A deep interest in how technology transforms the legal industry is highly valuable.

What you will find here:

• Competitive, equitable salary with top‑tier health benefits and dental coverage.
• Hybrid work environment, with expectation for local Clions to be in office min. twice per week.
• Flexible time off policy.
• Pension contribution.
• Clioversary recognition program with special acknowledgement at 3, 5, 7, and 10 years.

Diversity, Inclusion, Belonging and Equity (DIBE) & Accessibility: Our team shows up as their authentic selves, and are united by our mission. We are dedicated to diversity, equity and inclusion. We pride ourselves in building and fostering an environment where our teams feel included, valued, and enabled to do the best work of their careers.

Recruitment Process: We're a Human and High Performing AI company, meaning we use artificial intelligence to improve all of our operations. In recruitment, AI helps us streamline the process for greater efficiency.