High Volume (TOFU) Recruiter

The future of AI — whether in training or evaluation, classical ML or agentic workflows — starts with high-quality data.

At HumanSignal, we’re building the platform that powers the creation, curation, and evaluation of that data. From fine-tuning foundation models to validating agent behaviors in production, our tools are used by leading AI teams to ensure models are grounded in real-world signal, not noise.

Our open-source product, Label Studio, has become the de facto standard for labeling and evaluating data across modalities — from text and images to time series and agents-in-environments. With over 250,000 users and hundreds of millions of labeled samples, it’s the most widely adopted OSS solution for teams working on building AI systems.

Label Studio Enterprise builds on that traction with the security, collaboration, and scalability features needed to support mission-critical AI pipelines — powering everything from model training datasets to eval test sets to continuous feedback loops.We started before foundation models were mainstream, and we’re doubling down now that AI is eating the world. If you're excited to help leading AI teams build smarter, more accurate systems — we’d love to talk.

Level: Individual Contributor Compensation: $55,000 – $100,000 Location: San Francisco, CA preferred; open to other remote options

About the Role

HumanSignal Services runs on expert talent — and we need a lot of it, fast. As our high-volume recruiter, you are the engine that keeps our data programs fully staffed with the right contributors at the right time. This isn't a post-and-pray recruiting role. You'll be proactive, scrappy, and relentless — sourcing, screening, and moving candidates through a pipeline that never stops. When a program needs 500 vetted domain experts in 72 hours, you're the one who makes it happen. Speed matters here, but so does quality — the wrong contributor wastes everyone's time and hurts the data. You'll own both.

What You'll Do

You'll run high-volume sourcing across multiple channels simultaneously — job boards, LinkedIn, niche communities, referral networks, and anywhere else qualified talent lives. You'll screen candidates quickly and accurately, matching domain expertise to program requirements. You'll own pipeline health metrics — application volume, time-to-fill, screen-to-hire ratios — and hold yourself accountable to them daily. You'll work hand-in-hand with Strategic Project Leads and Operations to understand what each program actually needs, not just what the job description says. When a pipeline dries up or a new program spins up overnight, you don't wait to be told — you move. The programs don't stop for recruiting, so recruiting can't stop either.

Source and screen high volumes of candidates across multiple active programs simultaneously, maintaining quality and speed without sacrificing either

Own top-of-funnel pipeline health: track application volume, conversion rates, time-to-fill, and screen-to-hire ratios daily

Partner closely with Strategic Project Leads and Operations to understand program-specific requirements — domain expertise, availability windows, technical qualifications, and quality standards

Build and maintain sourcing pipelines across job boards, LinkedIn, academic networks, professional communities, and referral programs

Develop and iterate on outreach messaging, job descriptions, and screening criteria to improve conversion at every stage of the funnel

Coordinate scheduling and logistics for screening calls, assessments, and onboarding hand-offs

Flag pipeline risks early — if a program is at risk of understaffing, surface it before it becomes a delivery problem

Continuously improve sourcing strategies based on data; identify which channels produce the best contributors for each domain

Required Qualifications

2+ years of high-volume recruiting or sourcing experience

Proven track record managing large candidate pipelines under tight timelines

Strong organizational skills; comfortable juggling multiple open requisitions at once

Data-driven: comfortable tracking and reporting on funnel metrics

Excellent written communication for high-volume outreach and candidate engagement

Scrappy, self-directed, and comfortable operating with minimal process in a fast-moving environment

Preferred Qualifications

Experience recruiting for technical, domain-expert, or gig/contractor workforces

Familiarity with AI data operations, annotation, or RLHF workforce programs

Experience with ATS platforms (Greenhouse, Ashby, Lever, or similar)

Background in marketplace operations, staffing, or workforce platforms

About HumanSignal

HumanSignal Services specializes in operationally complex, multimodal data collection and annotation — delivering the datasets that frontier AI research requires and remote workforce marketplaces can't. We own projects end-to-end, from scoping and protocol design through final delivery, running on-site and distributed expert workforces across 50+ knowledge domains, 30+ languages, and 75+ countries. Our work spans RLHF, evals, red-teaming, and custom multimodal data creation, all powered by Label Studio Enterprise and built on a foundation of rigorous quality workflows, ethical sourcing, and full data security.