Lead AI & LLM Developer Team Lead

Lead AI \& LLM Developer / AI Team Lead

We are a progressive, forward-thinking agency group with multiple established businesses, ambitious growth plans and a genuine appetite for innovation.

Our experience spans marketing, media, automotive, technology, content and digital services - but our ambitions extend well beyond any one sector. We are developing AI and large language model-powered products that can transform our own businesses, create valuable new commercial services and solve challenges across a much wider range of industries.

Our multiskilled team brings together specialists from media, marketing, design, content, data, digital, sales and commercial strategy. We are naturally curious, excited by new technology and motivated by turning ambitious ideas into practical products with measurable commercial value.

We are now making a significant investment in our internal AI capability and are looking for an exceptional Lead AI \& LLM Developer to establish and lead our new development function.

The opportunity

Working directly with our CEO, senior leadership team and specialists across the group, you will take new AI products from discovery and technical validation through to live deployment, adoption and continued commercial development.

Initially, you will be a highly hands-on technical lead, taking ownership of our architecture, development roadmap and first core products. As the function grows, you will help recruit, mentor and lead a wider internal AI team.

This is not a maintenance position, a purely strategic role or an opportunity focused on producing isolated proofs of concept. You will combine technical leadership with hands-on development and will be accountable for turning viable ideas into dependable products that people can use.

What you will be responsible for

• Defining our technical vision, architecture and AI development roadmap
• Translating commercial opportunities and operational challenges into clear product and technical requirements
• Leading products from discovery and prototyping through to production deployment
• Building minimum viable products and scalable, production-ready applications
• Designing applications powered by large language models
• Working extensively with Anthropic Claude, OpenAI, Google Gemini and other suitable models
• Selecting models based on quality, reasoning ability, speed, security, context capacity and cost
• Designing advanced system prompts, context strategies and reusable prompt architecture
• Building structured outputs, function calling, tool use and agentic workflows
• Developing retrieval-augmented generation systems, embeddings, vector databases and governed knowledge bases
• Connecting AI applications to business systems, websites, databases, CRM platforms and third-party services
• Establishing effective guardrails, fallback behaviour and human-review processes
• Protecting applications against prompt injection, data leakage, inappropriate tool use and unsafe outputs
• Creating evaluation frameworks for accuracy, relevance, consistency, hallucinations, bias and task completion
• Building automated regression testing so changes to prompts or models can be measured safely
• Monitoring deployed systems for quality, reliability, latency, token consumption and cost
• Determining when prompting, RAG, model routing, fine-tuning or a conventional software solution is most appropriate
• Exploring multimodal AI involving text, images, documents, audio and video
• Supporting the development of voice-AI applications where relevant
• Designing secure APIs, back-end services, data pipelines and cloud infrastructure
• Managing deployments, version control, technical documentation and system observability
• Applying GDPR, security and responsible-AI principles throughout the development lifecycle
• Protecting company intellectual property, code, data, prompts and product knowledge
• Leading controlled testing with internal teams, customers and prospective users
• Measuring adoption, business value and product performance following launch
• Setting realistic budgets, resources, milestones and delivery timescales
• Reporting progress, risks, dependencies and decisions clearly to the leadership team
• Recruiting, mentoring and leading developers and AI specialists
• Establishing coding, testing, documentation and responsible-AI standards for the team

Essential LLM expertise

You must have extensive hands-on experience designing and deploying applications powered by large language models.

This should include

• A strong understanding of tokens, context windows, inference settings and model limitations
• Advanced system prompting and context engineering
• Anthropic Claude and the Anthropic API
• OpenAI models and APIs
• Google Gemini or other leading foundation models
• Structured outputs, function calling and tool use
• Agentic and multi-stage LLM workflows
• Model Context Protocol or comparable tool-connection methods
• Retrieval-augmented generation
• Embeddings, semantic search and vector databases
• LLM evaluation, benchmarking and observability
• Guardrails and application-level AI safety
• Prompt-injection and data-leakage protection
• Prompt caching, token optimisation and API-cost management
• Model routing and model comparison
• Understanding when fine-tuning is appropriate
• Monitoring and improving live LLM applications after deployment

Experience using AI through consumer interfaces alone will not be sufficient. You must understand how to engineer LLMs into controlled, secure and commercially dependable products.

Wider technical experience

You will ideally have substantial experience across several of the following:

• Python and modern software-engineering practices
• TypeScript, JavaScript or relevant full-stack technologies
• API architecture and third-party integrations
• AWS, Microsoft Azure or Google Cloud
• Relational and non-relational databases
• Secure and scalable application architecture
• Git and collaborative development workflows
• Automated testing and CI/CD
• Logging, monitoring and application observability
• Authentication, permissions and secrets management
• Data governance, GDPR and cybersecurity
• Production deployment and ongoing application support

Experience with LangChain, LlamaIndex, LangGraph or comparable frameworks would be useful, although sound engineering judgement is more important than dependence on one framework.

Proven delivery is essential

This is a senior appointment. Applicants must demonstrate successful delivery of AI-powered or technically complex products and management of a team.

You should be able to evidence

• LLM or AI applications you personally designed and built
• Products that progressed beyond experimentation into live operational or commercial use
• Your individual technical contribution and level of ownership
• The architecture, models and infrastructure you selected
• How you managed accuracy, security, safety, performance and cost
• How you addressed unreliable model behaviour and technical failure
• Continued product improvement following testing and user feedback
• Successful collaboration with commercial and non-technical stakeholders
• Measurable outcomes such as adoption, revenue, efficiency, cost reduction or customer value
• Experience leading developers, suppliers or multidisciplinary technical teams

We do not expect candidates to have trained a foundation model from the ground up. We do expect extensive experience building valuable applications around LLMs and related AI technologies.

The person we are looking for

You will

• Be genuinely excited by AI and the speed of technological change
• Combine experimentation with strong technical discipline
• Understand the difference between an impressive demonstration and a viable commercial product
• Challenge assumptions and recommend better approaches
• Communicate complex technology clearly to non-technical decision-makers
• Take ownership from initial scoping through to successful delivery
• Identify risks before they affect security, cost or delivery
• Be comfortable working directly with senior business leaders
• Enjoy collaborating with specialists from different disciplines
• Recognise opportunities that could benefit multiple businesses and sectors
• Be capable of building and leading a high-performing team
• Care about user experience as well as technical performance

Why join us?

We offer

• The opportunity to establish and lead a new internal AI development function
• Genuine ownership of products from concept through to commercial launch
• Direct access to the CEO and senior decision-makers
• The opportunity to recruit and shape your future team
• Exposure to multiple businesses, sectors and commercial opportunities
• Access to genuine operational challenges and potential test users
• Collaboration with specialists across marketing, media, design, content, digital, data and strategy
• Significant scope for the role, team and remuneration to grow
• A warm, welcoming and fun working environment
• A culture where ideas, initiative and intelligent experimentation are encouraged
• Office-based collaboration Monday to Thursday
• The option to work from home on Fridays
• Plenty of free on-site parking
• Company benefits and employee perks
• The stability of an established group combined with the energy of a new technology venture

How to apply

Please submit your CV with a portfolio covering two or three successfully delivered projects.

For each project, please include

• The business problem or commercial opportunity
• What you designed and built
• Whether it reached live deployment
• Your personal responsibilities and contribution
• The models, platforms and technologies used
• Your approach to prompting, RAG, testing, guardrails and evaluation
• The timescale and team structure
• Significant technical challenges and how you resolved them
• Measurable commercial, customer or operational results
• A product, demonstration, case-study or repository link where confidentiality permits

Shortlisted applicants may be asked to complete a relevant technical assessment and discuss their previous projects in detail.

Pay: £60,000.00-£90,000.00 per year

Benefits

• Additional leave
• Casual dress
• Company events
• Company pension
• Free parking
• On-site parking
• Sick pay
• Work from home

Work Location: In person