Senior AI Engineer

AI Engineer – LLMs / Applied AI

London (onsite)

Salary up to £180k + equity

We’re working with a fast-growing AI startup building proprietary algorithms that are redefining how complex knowledge work is done.

With strong revenue traction, top-tier investors, and a deeply technical founding team, this is a chance to help build a category-defining company from the inside.

What you’ll be responsible for:

  • Designing, building, and deploying production-grade AI algorithms that materially improve output quality in real-world applications
  • Owning state-of-the-art evaluation pipelines to benchmark models, guide R&D, and support rapid iteration
  • Researching and implementing advanced prompt engineering and LLM interaction techniques
  • Working across the stack (primarily Python, but also Postgres and React) to ensure research translates cleanly into customer-facing product
  • Moving fast from idea to production, with direct customer feedback loops

The environment:

  • High-ownership, low-ego team of AI researchers and elite engineers
  • Strong commercial traction with hundreds of enterprise users globally
  • Recently closed a major funding round from top-tier investors
  • Ambitious, execution-focused culture with very high engineering standards

What we’re looking for:

Must-haves:

  • Deep Python expertise and experience shipping AI systems into production
  • Hands-on experience with LLMs, prompt engineering, and modern model architectures
  • Proven track record building evaluation frameworks or ML pipelines used in live environments
  • Comfort working end-to-end across the stack
  • Clear communicator who can reason about complex technical trade-offs
  • 4+ years experience total

Nice-to-haves:

  • Publications at top ML conferences (NeurIPS, ICLR, ICML)
  • Experience with LLM evaluation tooling (e.g. OpenAI Evals or similar)
  • Strong GitHub presence or technically ambitious side projects

What’s on offer:

  • Salary up to £180k + meaningful equity
  • Work directly with a highly technical founding team
  • Visa sponsorship and private medical insurance
  • London-based, high-performance office environment with meals provided
  • Opportunity to help shape a product and company with genuine breakout potential

Apply below!

Job Details

Company
Harnham
Location
London Area, United Kingdom
Posted