Research Engineer, Judgment Systems

Research Engineer, Judgment Systems at Variance — San Francisco, US

  • Company: Variance
  • Location: San Francisco, US
  • Employment type: FULL_TIME
  • Posted: 2026-07-17

About this role

Role

At Variance, we are teaching machines to make the hardest judgment calls at scale. We build AI agents for the high-precision gray area of stopping fraud, scams, and abuse. This isn't another sales tool or a customer service system. We're solving real problems in investigations and fraud prevention to protect innocent people from being harmed.

We’re a small, talent-dense team in San Francisco working on a problem at the edge of what AI systems can reliably do: making good decisions in messy, adversarial, real-world environments.

We’re looking for a Research Engineer to help push that frontier forward. You’ll design evals, study failures, build new research loops, and turn research ideas into production capabilities.

This role sits at the intersection of research and engineering: part model builder, part experimentalist, part systems engineer.

You’re a fit if you:

Care deeply about protecting people from fraud, scams, and abuse

Have strong opinions about model quality, evaluation, and experimental rigor

Want to work on core model and agent behavior

Are excited to train, fine-tune, and improve models for hard real-world judgment tasks

Think in tight research loops: hypothesis, experiment, evaluation, failure analysis, iteration

Thrive in ambiguous, fast-moving environments where the path is not obvious and the feedback loop is short

Are motivated by the challenge of making AI systems work in adversarial, regulated, and high-consequence settings

Want to help define what trustworthy AI means in real-world use cases

What you’ll do

Train, fine-tune, and improve models for fraud, scams, abuse, and other high-stakes judgment workflows

Own research threads focused on improving agent capability, reliability, and decision quality

Build proprietary benchmarks, datasets, and evals that reflect real customer workflows, regulatory constraints, and real failure modes

Design and run experiments across post-training, retrieval, tool use, planning, memory, and long-horizon agent behavior

Study where models break, why they break, and how to make them more robust

Prototype new training strategies, agent architectures, and evaluation methods, then turn the best ideas into production systems

Work closely with founders and engineering to translate research advances into deployed product capabilities

Push the boundary of what AI agents can do in regulated industries

What success looks like

Our models get materially better at making hard judgment calls in production

Our models are trusted at scale

We develop evals and training loops that compound over time

We understand failure modes more clearly and improve system behavior faster

New research ideas turn into real product capabilities quickly

Preferred background

Experience training, fine-tuning, or evaluating modern ML systems

Strong programming skills and comfort working in research-heavy codebases

Familiarity with LLMs, agent systems, post-training, reinforcement learning, retrieval, or adjacent areas

Ability to design clean experiments and draw reliable conclusions from noisy results

Strong engineering judgment and a bias toward building

Interest in fraud, risk, trust and safety, compliance, or other regulated and adversarial domains

Our culture

We believe in ownership, urgency, and craft. We enjoy spirited debate, wild ideas, and building things we’re proud of. We’re fully in-person in San Francisco.

What we offer

Competitive salary and meaningful equity

Platinum-level medical, dental, and vision insurance

Unlimited PTO, sick leave, and parental leave

Up to $100 per month in reimbursement for personal health and wellness expenses

401(k) plan

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