Senior Machine Learning Engineer

About the role

We are looking for a Senior Machine Learning Engineer to help build and ship the next generation of our Customer Experience Intelligence platform. You will work on custom models for customer feedback, leveraging both proprietary and off‑the‑shelf LLMs.

Key responsibilities

• Design, train, evaluate and iterate on transformer‑based models and agentic systems for extraction, retrieval, reranking, summarisation and sentiment analysis.
• Develop and maintain LLM‑powered features such as retrieval pipelines, insight agents and automated taxonomy generation.
• Build robust evaluation frameworks, create test sets, define metrics and automate model comparisons.
• Write production‑grade code, collaborate with engineering on model serving, data pipelines and monitoring.
• Partner with product and commercial teams to translate business needs into ML solutions and support client evaluations.
• Mentor junior team members, review code and integrate state‑of‑the‑art research into the product.

Required profile

• Deep working knowledge of transformer architectures and strong PyTorch expertise.
• Experience with large‑scale, messy text data, including classification, extraction, embeddings and search.
• Proven ability to build and fine‑tune LLMs using techniques such as LoRA and to serve them with frameworks like vLLM or DeepSpeed.
• Solid grounding in classical machine learning, statistics and the judgement to choose simpler methods when appropriate.

Required skills

• Transformer architectures
• PyTorch
• Parameter‑efficient fine‑tuning (LoRA)
• Large‑scale text data processing
• vLLM / DeepSpeed
• Classical machine learning and statistics
• Generative AI and agentic patterns

What we offer

• Equity scheme and performance‑based options.
• Monthly health & wellness budget, increasing with tenure.
• Annual learning & development budget.
• Flexible working – remote or hybrid, with a work‑from‑home allowance.
• 25 vacation days plus local holidays, birthday off and extra day per year of service.
• Enhanced family, fertility and neonatal leave (UK only), optional healthcare plan and life‑income protection.
• Dog‑friendly London office with rooftop terrace.