CareerPlan

Principal Applied Scientist

United Kingdom, London, LondonFull-time2026-10-27 → 2026-11-10

Core

Design and run experiments to develop scalable retrieval pipelines and models for enterprise-scale search systems, including semantic, lexical, and hybrid retrieval, RAG, and agentic AI architectures.

Role type

Principal Applied Scientist (Retrieval Science)

Builds

Enterprise-scale search systems, retrieval pipelines, and LLM-integrated retrieval architectures

Domain

Search, Information Retrieval, Large Language Models (LLMs), Agentic AI

Deliverable

production ML models

Required skills

Semantic retrieval (late-interaction architectures), Dense retrieval, Embedding model fine-tuning, SPLADE/sparse retrieval, Hybrid retrieval systems, Query understanding, Multi-stage ranking, RAG, Reinforcement learning, LLM-integrated architectures, Python, PyTorch, Offline/online evaluation metrics, Scalability optimization

Preferred skills

Publications in top-tier conferences (SIGIR, RecSys, KDD, WWW, WSDM, ACL, EMNLP), Experience with agentic AI systems, Personalization and contextual ranking

Technologies

ColBERT, SPLADE, PyTorch, Python, LLMs

Responsibilities

Develop scalable retrieval pipelines and models, Define offline and online evaluation metrics, Provide technical leadership and mentorship, Establish and evolve evaluation frameworks for retrieval quality and Copilot metrics

Seniority

Principal, hands-on IC with mentorship