Full Stack AI Engineer

About the role

We are looking for a Senior Full Stack AI Engineer to join our AI team and help us build cutting-edge legal solutions for some of the worlds largest law firms.

In this role you will leverage your deep expertise in machine learning natural language processing large language model (LLM) agents and programming alongside full stack development to push the boundaries of legal technology. Youll be collaborating closely with ML engineers software engineers and domain experts to integrate advanced NLP techniques into our products and deliver end-to-end user-facing experiences.
You have strong front-end (JS) and back-end ( etc.) development skills and are comfortable working across both backend systems and user-facing interfaces taking ownership of features from idea to production.

Its a role for someone who is comfortable working in a fast-paced sometimes ambiguous environment enjoys solving complex problems and wants to have a direct impact on product and technical direction.

What youll do:

• Designing and deploying LLM agents and agentic architectures to automate complex legal workflows

• Building and maintaining scalable production-grade systems that are reliable secure maintainable and observable

• Working across the full stack to integrate AI capabilities into user-facing products

• Owning features end-to-end from prototyping through to production and iteration

• Collaborating closely with ML engineers software engineers and domain experts to bring AI-driven features into the product

• Contributing to the direction of our AI initiatives by staying up to date with developments in NLP machine learning agentic systems and full stack technologies

What youll bring:

• Experience working with LLMs in production and integrating ML/LLM components into product systems (streaming async jobs state caching evaluation)

• Strong Python ( C# as well) backend development skills with experience building APIs and services and comfort contributing to front-end applications

• A solid understanding of software development principles including design patterns data structures and algorithms

• Experience using AI tools (such as Claude Code Cursor Codex) and interest in leveraging them to improve engineering efficiency

• Strong communication skills with the ability to explain complex technical concepts clearly to both technical and non-technical audiences

• A strong appreciation of Kubernetes Infrastructure as Code GitOps CI/CD practices and cloud infrastructure (AWS or GCP)

• Comfort working in a fast-paced sometimes ambiguous start-up environment with changing priorities

What we can offer you:

• Competitive salary & annual bonus

• Share options

• Quarterly team socials & annual company offsite

• Hybrid working 1 month work from anywhere

• 25 days holiday bank holidays

• Take your birthday off

• 750 annual learning & development budget

• Private healthcare (incl. dental & optical)

• Enhanced parental leave

• Additional perks: Cycle to Work Workplace Nursery salary sacrifice scheme and top-quality equipment

About Definely

Definely is revolutionising how legal professionals access and understand information in complex documents. Our LegalTech solutions integrate directly into legal workflows enabling teams to draft review and interpret contracts more efficiently without breaking focus.

Were proud to be recognised among the Top 25 in Deloittes UK Technology Fast 50 and backed by Revaia Microsoft Google and Octopus Ventures. Trusted by top firms like A&O Shearman Dentons Deloitte and Barclays were building tools that empower legal teams to work smarter and reduce risk.

At Definely youll be part of a mission-driven collaborative and ambitious team committed to innovation and growth.

Data Privacy Notice

By submitting your application you agree that DEFEYENE LEGAL SOLUTIONS LIMITED (Definely) may collect process and store your personal data as part of our recruitment process. We will use the information you provide to assess your qualifications for the role you are applying for and to communicate with you regarding your personal data will be stored for up to 12 months after which it will be securely deleted unless we have another lawful basis to retain it. You have the right to access correct or request the deletion of your data at any more details on how we handle your personal data and your rights please send us an email to and we will send your our privacy policy.

If you have any concerns about how your data is being processed please do not hesitate to contact us.

Required Experience:

IC