Principal AI Scientist (all genders)

Description

The company Assistant team is hiring a Principal AI Scientist to build conversational shopping experiences on top of large language models (LLMs) and intelligent agents. The work covers fashion discovery, trend exploration, outfit recommendations and shopping conversations.

You will help shape the architecture and capabilities of the assistant, working on AI agents, retrieval-augmented generation (RAG) pipelines, prompt engineering and LLM integrations so that conversations stay grounded and engaging. The role covers the whole customer journey, from activation and engagement to retention and conversion.

This is a hands-on position with direct effect on customer-facing products. You will build and improve production AI agents that millions of customers use, working with product and engineering partners to lift product discovery, recommendation relevance and purchase conversion.

You will help build a culture of experimentation, with every assistant change checked through both offline and online metrics. Your work will feed into engagement, retention and long-term customer value.

The company is committed to hiring on merit. Candidates are assessed only on qualifications and experience, and you may leave photos, age and marital status off your application. If you need any accommodation during the hiring process, tell us so we can support you.

Responsibilities

• Build conversational AI agents from the ground up.
• Create and connect RAG pipelines that bring in current, relevant data.
• Write, tune and assess LLM prompts to raise answer quality and engagement.
• Connect LLMs to search, recommendation systems and external APIs.
• Define and build frameworks that measure conversation quality and grounding.
• Run experiments and tune the assistant against conversion, engagement and retention targets.
• Own the design, build and release of LLM-powered agent workflows.
• Work across engineering, product and data science teams.
• Coach colleagues and share good practice in applied AI and agent development.

Requirements

• 10+ years of experience in engineering or applied science.
• Strong Python skills and experience building production-grade applications.
• Strong analytical and problem-solving skills.
• Experience tuning AI systems against business KPIs.
• Strong plus, if you have any of the following: experience building LLM-powered applications or AI agents; experience with prompt engineering, tuning and evaluation; experience with agent frameworks such as LangChain, LlamaIndex, PydanticAI, DSPy or similar; experience connecting LLMs to external APIs, tools and/or RAG systems; experience with vector databases, embeddings or retrieval systems.
• A plus, if you have experience assessing conversation quality and defining LLM metrics.

Conditions

Hybrid working model with at least 60% remote work per week; the exact in-office practice is set by each team to suit how it collaborates.

Work from abroad for up to 30 working days a year.

Relocation assistance is available, subject to prior agreement.

Benefits

• Employee shares program.
• 40% off fashion and beauty products sold and shipped by the company, 30% off the company Lounge and discounts from external partners.
• 2 paid volunteering days a year.
• 27 days of vacation a year to start.
• Family services, including counseling and support.
• Health and wellbeing options, including Gympass.
• Mental health support and coaching.
• Training through the company's learning platform and a peer-to-peer review twice a year.