Senior Applied Scientist - LLMs in AdTech

Do you want to build ML and LLM products that directly impact revenue at scale?

Have you taken ML models from idea to production in a fast-paced environment?

Are you ready to own 0-1 AI capabilities in a high-growth SaaS business?

A fast-scaling, VC-backed SaaS company is building advanced machine learning systems to detect and prevent invalid traffic and ad fraud. Operating at massive data scale, they sit at the intersection of ML, data engineering, and adversarial systems. Data science is central to their product innovation, with a strong focus on real-world impact over research.

This is a Senior Applied Scientist role focused on building new AI-driven product capabilities end-to-end. You will prototype, validate, and productionise ML and LLM-based solutions that directly improve customer outcomes.

Key Responsibilities

• Own 0-1 ML product development from prototype to production

• Build and scale LLM systems (RAG, agents, NLP)

• Translate product needs into experiments, MVPs, and production features

• Collaborate with Engineering and Product to ship solutions

• Work with large-scale cloud datasets to drive insights and models

• Apply ML techniques pragmatically for business impact

Key Details

• Salary: £70k–£90k + benefits

• Working model: Hybrid (2 days onsite, London or Manchester)

• Tech stack: Python, SQL, LLMs, AWS/GCP (SageMaker, Bedrock, etc.)

• Visa: Cannot sponsor

Interested? Please apply below.