Job Description

Senior / Staff Applied AI/ML Research Engineer – London - £200,000 – £300,000 + bens + shares. In-Office (5 days, flexibility at Staff level) Series D | 250 Employees | High-Growth AI Company

Senior / Staff Applied AI/ML Research Engineer to join foundational research team at one of the fastest-scaling conversational AI platforms in the market.

Backed by a number of well-known VC's, the company has raised $200M+ and is scaling toward nine-figure revenue by 2026.

This is not an API wrapper role. This is proprietary model development powering 80% of platform traffic.

You’ll report to the Research Lead as part of a highly specialised ML team (currently 5, scaling to 10 in the next 6–12 months). This is the only team building foundational models critical to company success.

What You’ll Do

• Design and implement state-of-the-art instruction tuning methods
• Fine-tune and deploy LLMs in production environments
• Apply reinforcement learning techniques (SFT, PPO, DPO, GRPO)
• Run hands-on experimentation to outperform closed-source models
• Break down ambiguous research ideas into structured roadmaps
• Optimise open-source LLMs (LoRa, Llama etc.) for enterprise deployment

One hire will focus specifically on voice and speech systems.

Ideal Background

• 5–7+ years in applied AI/ML (exceptional 3+ years considered)
• Deep experience in fine-tuning + reinforcement learning
• Experience shipping ML systems from research into production
• Open-source LLM experience essential
• Product-driven engineering mindset (Apple, LinkedIn, Amazon style environments ideal but must be willing to work in a start-up with large degrees of ambiguity) 

Why join?

Foundational Impact – This is the only team building core proprietary models.
Real Product-Market Fit – Rapid growth, major enterprise clients.
Revenue Trajectory – Targeting nine-figure revenue in 2026.
High Ownership – Applied research with direct production impact.
Top Compensation – £200k–£300k.
Benefits – Medical, dental, vision + daily in-office meals + flexible vacation policy.

If you want applied research that ships, not just publishes, this is a rare opportunity.

To apply or learn more, send your CV to Nathan Laidlaw at Transparent Tech.

All client details are handled confidentially and shared at the appropriate stage.

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