Applied AI Builder · Quantitative Analyst · San Francisco Bay Area

I build AI-powered tools, agents, and workflow automations — validated with the same rigor I bring to risk models.

I work at the intersection of quantitative analytics, model validation, and applied AI — turning repetitive analytical and business workflows into structured, reproducible, human-reviewed systems.

Track record CoStar Risk Analytics Guidehouse Federal Analytics Federal Reserve Board Penn MAS-CS
Yullie Yang

What I do

Three angles on one question: can this output be trusted?

The same validation discipline runs through everything I work on — whether the output comes from a credit model, an experiment, or an LLM.

AI & LLM Evaluation

Measuring whether LLM and agent workflows stay grounded, calibrated, and safe enough for a person to act on.

  • RAG evaluation
  • LLM / agent eval
  • confidence calibration
  • grounding checks
  • human-in-the-loop
  • failure-mode analysis

Risk & Model Validation

Testing model outputs against scenarios and stress conditions before they inform a decision.

  • model validation
  • stress testing
  • scenario analysis
  • sensitivity analysis
  • model monitoring
  • credit-risk analytics

Experimentation & Metrics

Designing experiments and metrics that separate real effects from noise and guardrail risk.

  • A/B testing
  • power / MDE
  • CUPED
  • SRM checks
  • metric design
  • segmentation

The path

Policy analytics to model risk to AI evaluation

Each role added a piece of the same skill: making analytical outputs traceable, testable, and safe to decide on.

2023 · Foundation

Federal Reserve Board

High-stakes policy & macro-financial analytics

NLP / doc analysisPython automationresearch tooling

Learned how analytical work holds up when it feeds policy — where being wrong is expensive and evidence has to be traceable.

2024–25 · Applied AI

Guidehouse

Federal analytics, RAG & LLM workflows

RAG evaluationLangChain / LangGraphfailure-mode docs

Started evaluating AI systems directly — measuring retrieval quality and documenting where LLM workflows break.

2025–now · Model risk

CoStar Group

Credit-risk model validation & monitoring

stress testingmodel QArelease readiness

Own the discipline of validation — QA, monitoring, and stress-testing model outputs before they ship.

Direction

AI Evaluation & Risk

Decision reliability for AI systems

AI evaluationmodel risktrust & safety

The same validation mindset, applied to whether AI systems are reliable enough to trust.

Selected quantitative & applied AI work

Projects, framed by what they evaluate

Each one is a small, reproducible study of whether a system does what it claims — with the methods and the verdict made explicit. The applied-AI work above is built on the same discipline.

treatment +0.84pp control days since exposure →

Experimentation

Product Experimentation & Metrics Analysis

Whether a simulated feed-ranking change improves 7-day retention without moving guardrail metrics the wrong way.

  • 100K users
  • SRM check
  • power / MDE
  • CUPED
  • segmentation
  • launch call

Why it mattersSound product decisions need both a statistical result and judgment about which metrics actually matter.

baseline adverse severe

Risk Analytics

CRE Stress Testing Workflow

How macro and market stress scenarios move commercial-real-estate risk indicators, using only public data.

  • scenario analysis
  • stress testing
  • forecasting
  • model monitoring
  • reproducible pipeline

Why it mattersA risk model is only useful if its outputs can be tested across changing economic conditions.

history 8-qtr forecast

Macro Forecasting

R Macro Trade & Commodity Forecast

Macro, trade, and commodity indicators built from FRED data in a reproducible R pipeline.

  • FRED
  • ARIMA
  • distributed-lag regression
  • Quarto
  • GitHub Actions

Why it mattersConnects the macro-policy side of my background to versioned, reproducible analytical tooling.

data QA review code review checklist brief review human sign-off

Workflow & Documentation

LLM Research Workflow Assistant

Reusable prompt templates and human-in-the-loop checklists that package recurring research-support tasks — data QA, code review, brief review, documentation — into a consistent, reviewable workflow.

  • prompt templates
  • worked examples
  • human-in-the-loop
  • responsible-use docs

Why it mattersShows the same building discipline on a lighter workflow: packaging AI assistance so it stays consistent and reviewable instead of ad hoc.

Where the work has been

I've worked across policy, federal analytics, and private-sector risk — environments where an analytical output has to be reproducible, explainable, and ready to stand behind a decision.

Federal Reserve Board

Policy environment

Macro and regulatory analysis where conclusions inform policy, so every step has to be traceable back to its evidence.

Guidehouse

Federal analytics

Multi-source financial data and early LLM / RAG evaluation, under compliance constraints and formal documentation.

CoStar Group

Private-sector risk

Credit-risk models under stress testing, monitoring, and release review before their outputs reach a decision.

Toolbox

Methods and tools I work with

Languages

  • Python
  • SQL
  • R
  • JavaScript / Node.js

AI / LLM Evaluation

  • Claude API
  • RAG evaluation
  • LLM evaluation
  • agent workflows
  • prompt experimentation
  • human-in-the-loop review
  • retrieval-quality analysis

Analytics & Experimentation

  • A/B testing
  • CUPED
  • SRM checks
  • power / MDE
  • metric design
  • forecasting

Risk & Model Validation

  • stress testing
  • sensitivity analysis
  • model monitoring
  • credit-risk analytics

Engineering

  • Git
  • GitHub Actions
  • Streamlit
  • Pydantic
  • Puppeteer
  • Quarto
  • pytest
  • SQLAlchemy

Visualization

  • Tableau
  • Power BI
  • Streamlit dashboards
  • Quarto

Get in touch

Focused on Bay Area roles in applied AI, workflow automation, and model risk

I'm relocating to the San Francisco Bay Area and actively looking for teams building practical AI tools and automations — with the same rigor for validation, reproducibility, and human review that I bring to risk models. If that's you, let's talk.

Based in Boston · relocating to the San Francisco Bay Area