AI Software Engineer

Location: Watford, United Kingdom

Company

Zellis develops HR and payroll software and managed services used by organisations across the UK and Ireland.

What you will do

• Design, build, and maintain AI-powered applications and integrations within the ZellisONE technology stack.
• Contribute to the AI engineering approach, including prompt engineering, RAG, semantic data retrieval, chain-of-thought, ensemble models, fine-tuning, RLHF, agentic workflows, and MCP.
• Develop reusable full-stack software components using JavaScript, Python, Vue, and Node.
• Maintain code quality through reviews, best practices, GitHub collaboration, and usability-focused implementation.
• Develop AI testing processes, document outcomes, and support reliable and reproducible evaluation.
• Contribute to CI/CD pipelines, manage delivery milestones, and report project status, risks, and outcomes.

Requirements

• Strong proficiency in JavaScript and Python.
• Solid understanding of SQL and working knowledge of GitHub.
• Experience with automated and unit testing frameworks.
• Familiarity with AI and code-assistance tools such as Codex and Cursor.
• Strong understanding of software usability principles, analytical problem-solving, communication, and collaboration.
• Ability to deliver high-quality work to tight deadlines in an agile, product-focused environment.

Culture & Benefits

• Inclusive, flexible, and supportive working environment.
• 25 days of annual leave, a birthday day off, and the option to buy additional holiday.
• Private medical insurance and life assurance at four times salary.
• Enhanced pension scheme with company contributions of up to 8.5%.
• Flexible benefits covering financial and personal wellbeing, lifestyle, and leisure.