Research Engineer - Llms & Generative Audio

Harnham; Greater London; Hybrid; GBP 90,000 - 150,000; Full time

Job summary

Harnham, a global media company, is building a new internal AI Lab in London. They seek a Senior AI Engineer to own the development of production-grade LLM systems across fine-tuning, retrieval, summarisation, evaluation, and audio-first experiences.

You will collaborate closely with engineering, product and design teams to deliver greenfield AI solutions spanning text, voice, and multimodal interfaces, with a hybrid work pattern (3+ days in London).

Qualifications

• Experience building production-grade LLM systems with focus on quality and reliability.
• Experience with retrieval and summarisation components.
• Ability to design evaluation frameworks for hallucination and output quality.
• Experience developing audio-first AI products using TTS/STT.

Responsibilities

• Build and deploy production-grade LLM systems
• Design and optimise RAG and retrieval workflows
• Fine-tune models for tone, style, and output quality
• Develop audio-first AI products using TTS/STT workflows
• Build multimodal AI experiences across text, voice, and search
• Create evaluation frameworks for hallucination and response quality
• Prototype and iterate rapidly in a greenfield environment
• Working model: Hybrid (3+ days/week in London)

Skills

LLM systems

RAG workflows

Fine-tuning models

TTS workflows

STT workflows

Multimodal AI

Production-grade systems

Job description

Do you want to help build the next generation of AI-native content and audio experiences?

Have you built LLM systems where output quality, tone, and trust genuinely mattered?

Are you ready to work on multimodal AI products spanning text, voice, and conversational interfaces?

A globally recognised media and information business is building a brand-new internal AI Lab focused on next-generation AI-powered consumer experiences. This is a small, high-autonomy innovation team operating like a start-up inside an established international organisation.

The team is exploring how conversational AI, retrieval systems, audio experiences, and multimodal generation can reshape how users interact with content and information products. You’ll work closely with engineering, product, and design stakeholders on genuinely greenfield AI systems.

This Senior AI Engineer role is focused on building production-grade LLM systems across fine-tuning, retrieval, summarisation, evaluation, and audio-first AI experiences. It’s a hands-on role with strong ownership and the opportunity to influence the technical direction of a newly formed AI Lab.

Key Responsibilities

• Build and deploy production-grade LLM systems
• Design and optimise RAG and retrieval workflows
• Fine-tune models for tone, style, and output quality
• Develop audio-first AI products using TTS/STT workflows
• Build multimodal AI experiences across text, voice, and search
• Create evaluation frameworks for hallucination and response quality
• Prototype and iterate rapidly in a greenfield environment
• Working model: Hybrid (3+ days/week in London)