Senior Data Labeler

About us

TL;DR: We're looking for a Data Labeling Lead to build our annotation team from zero – setting quality standards, designing evaluation frameworks, and running the labeling operations behind our safety evals, RLHF, and benchmarks. You'll own quality, throughput, and cost while working side by side with our AI researchers.

White Circle is an AI Safety company building the safety, reliability, and optimization layer for AI systems. At the core of our platform are policies – simple natural-language rules that define what an AI model should and shouldn’t do. We automatically test, enforce, and continuously improve these policies at scale.

We’ve raised $11M from top funds, founders, and senior leaders at OpenAI, Anthropic, HuggingFace, Mistral, DeepMind, Datadog, Sentry, and others

We process over 100M+ API calls every month

We fine-tune and train our own LLMs so they run faster and cheaper than any open or proprietary model

We’re at a multi-million dollar run rate already having signed customers like Lovable and multiple neobanks. You’ll be joining at the most exciting time - early enough that the equity can be life changing but at a point where demand has been proven.

In this role, you will

Build from scratch and lead the Data Labeling team (hiring, coaching, and performance management)

Define annotation guidelines, quality standards, and evaluation frameworks

Develop quality assurance processes, calibration sessions, and auditing systems

Partner with AI researchers and engineers to translate research objectives into labeling workflows

Prioritise labeling projects based on business and research needs

Monitor operational metrics including quality, consistency, throughput, and cost

Improve annotation tooling, automation, and workflow efficiency

Lead complex AI evaluation projects, including safety, preference ranking, RLHF, policy evaluation, and benchmark creation

Analyse disagreement patterns and edge cases to improve guidelines and model performance

Manage vendor relationships and ensure consistent quality across distributed teams

Build reporting dashboards and communicate operational insights to leadership

Foster a culture of continuous improvement, accountability, and operational excellence

We're looking for someone who

Has experience leading data annotation or AI evaluation teams

Has strong operational and people management skills

Understands AI model evaluation, LLM behavior, and modern annotation workflows

Can design scalable processes without sacrificing quality

Communicates clearly across technical and non-technical teams

Thrives in fast-moving startup environments

You might be a great fit if you

Have managed annotation programs for LLMs, generative AI, or machine learning

Have experience with RLHF, preference data collection, safety evaluations, or benchmark creation

Have worked in Trust & Safety, AI Safety, Content Moderation, or ML Ops

Have managed distributed or global annotation teams

Have experience with vendor management and outsourcing operations

Bonus points

Familiarity with prompt engineering and AI safety policies

SQL, Python, or data analysis experience

Experience building internal annotation platforms or workflow automation

Background in linguistics, cognitive science, machine learning, or data operations

Important note

• This role involves overseeing projects that may include offensive, harmful, violent, sexual, or otherwise disturbing content.
• You'll be responsible for ensuring reviewers have the tools, guidance, and support necessary to perform this work safely and consistently.

Why White Circle

Competitive compensation package, including equity

Flexible time off

Paid time off in line with your local regulations, no matter where you work from

Work from Paris (hybrid) + relocation package

Best medical insurance in France

Learning and development support for courses, conferences, and opportunities to grow your skills

All the hardware, tools, and services you need

Covered subscriptions for AI agents and IDEs

Team off-sites twice a year: we’ve recently been to the Alps and to Saint-Tropez

Process

Intro call with HR (30 min)

Take-home test assignment

Final conversation with our CEO (45 min)

Please submit your application in English.