Senior AI Engineer

Harnham; Greater London; Hybrid; GBP 90,000 - 140,000; Full time

Job summary

Harnham in London is seeking a Senior AI Engineer to join a hybrid team, building production-grade LLM applications across text, audio and multimodal experiences.

You'll collaborate with product and engineering, fine-tune models, develop RAG pipelines, and shape evaluation frameworks to deliver high-quality AI products.

Qualifications

• Strong commercial experience building AI, NLP, or LLM-based products.
• Hands-on experience with modern foundation models and AI frameworks.
• Experience with fine-tuning, prompt engineering, or instruction tuning.
• Strong Python engineering skills.
• Experience evaluating and improving model performance.
• Excellent communication skills and ability to work with non-technical stakeholders.
• Experimental mindset and a passion for building high-quality AI products.

Responsibilities

• Build and fine-tune LLM-powered applications and services.
• Develop and optimise RAG pipelines.
• Deliver style and tone modelling solutions to improve LLM outputs.
• Support personalisation, summarisation, and real-time generation initiatives.
• Work closely with product, engineering, and business stakeholders.
• Contribute to multimodal and audio-focused AI projects.
• Help define evaluation frameworks and model quality standards.

Skills

LLM-based products

Python

NLP

Prompt engineering

Tools

PyTorch

Transformers

Job description

Senior AI Engineer

London (Hybrid)

A fantastic opportunity to join a world leading media company within a newly established AI Lab focused on building innovative Generative AI products. You'll work in a small, high-impact team developing production-grade LLM applications that influence how users interact with content across text, audio, and emerging multimodal experiences.

The Company

A globally recognised organisation with a large international audience is investing heavily in AI innovation. Their dedicated AI Lab is exploring the future of AI-powered products, combining cutting-edge technology with real-world user impact. This is an opportunity to help shape the direction of a fast-growing function from an early stage.

The Role

You will:

• Build and fine-tune LLM-powered applications and services
• Develop and optimise RAG pipelines
• Deliver style and tone modelling solutions to improve LLM outputs
• Support personalisation, summarisation, and real-time generation initiatives
• Work closely with product, engineering, and business stakeholders
• Contribute to multimodal and audio-focused AI projects
• Help define evaluation frameworks and model quality standards

Your Skills & Experience

• Strong commercial experience building AI, NLP, or LLM-based products
• Hands‑on experience with modern foundation models and AI frameworks
• Experience with fine-tuning, prompt engineering, or instruction tuning
• Strong Python engineering skills
• Experience evaluating and improving model performance
• Excellent communication skills and ability to work with non-technical stakeholders
• Experimental mindset and a passion for building high-quality AI products

Desirable experience includes speech technologies, generative audio, multimodal AI, or content-focused AI applications.

Desired Skills and Experience

Text-to-speech, LLMs