Curriculum Vitae
Quantitative ML practitioner: publications, production systems, and research.
Basics
- Name
- Zachariah Farahany
zfarahany193@gmail.com
LinkedIn- GitHub
ZachFara- Summary
- Quantitative ML practitioner with a research thread. I build, deploy, and research production ML and agentic systems. My background spans the full stack from data pipelines and model development to agentic LLM architectures and interpretability research, with first and co-author IEEE publications and production deployments across finance, insurance, and industrial IoT. Currently a Quantitative Analytics Associate at Wells Fargo working on production credit risk models and quantitative risk systems.
Publications
Oversampling Techniques for Predicting COVID-19 Patient Length of Stay
Venue: IEEE Big Data 2022
Authors: Zachariah Farahany, K M Sajjadul Islam, Jiawei Wu, Praveen Madiraju
arXiv: arXiv:2511.15048
GitHub: ZachFara/Oversampling-Techniques-for-Predicting-COVID-19-Patient-Length-of-Stay
Role: First author
- Binary classification of hospital length of stay (>7 days) as a severity proxy for resource allocation, on a high-dimensional sparse EHR dataset (n=11,235, ~25,000 features after processing).
- ANN with Bayesian hyperparameter optimization and SMOTE-style oversampling on an imbalanced ~80/20 class split.
- Best model reached 85.79% F1 (95.50% accuracy, 91.23% AUC), outperforming comparable published benchmarks of 49–80% F1.
A Machine Learning Approach to Predict Length of Stay for Opioid Overdose Admitted Patients
Venue: IEEE Big Data 2021
Authors: Jiawei Wu, Priyanka Annapureddy, Zach Farahany, Praveen Madiraju
DOI: 10.1109/BigData52589.2021.9671933
Role: Co-author
- Contributed experimental design, methodology review, and results communication on a length-of-stay prediction problem applied to opioid overdose patients.
Work
2025.07 – present
Quantitative Analytics Associate
Company: Wells Fargo
- Selected into a competitive rotational development program rotating across lines of business, with formal training in banking, finance, and regulation.
- WIM Model Risk (Jan 2026 – Jul 2026): Validated the tracking-error prediction model used for risk projection across Wells Fargo wealth-management client portfolios, benchmarked against BlackRock Aladdin.
- Implemented and compared multiple factor models (Fama-French 5-factor, a 12-factor model, full sample covariance, experimental PCA factors) from research papers, with research-based extensions focused on covariance and volatility scaling — market-cap covariance scaling, EWMA weighting, and Barra-style GARCH/GJR-GARCH and MF2-GARCH volatility scaling — that improved tracking-error accuracy.
- Built a full backtesting engine supporting fixed and varying benchmark/portfolio configurations, plus a Dirichlet-based testing-portfolio construction method that holds portfolios market-cap weighted on average while modeling realistic variance across the client base.
- Risk Modeling Group, Auto Decisioning (Jul 2025 – Dec 2025): Built and shipped to production the second-stage Eagle model, a probability-of-charge-off model that makes the final approve/decline decision on all Wells Fargo auto originations.
- Handled variable selection for fairness compliance, monotonicity validation against drivers like FICO, and segment-level error analysis on realized vs. predicted charge-off.
- Separately built an automated auditing tool for credit-bureau attributes, replacing a manual process that required a team of ten analysts working multiple weeks.
- The tool parses the attribute specification sheet, applies its rules to applicant credit histories, and reconciles against the data provider, raising validated coverage from under 1% of applicants to 25%+ in a single day.
2025.01 – 2025.05
AI Engineer (Contract)
Company: Seyon Solutions
- Architected and built from scratch an agentic LlamaIndex assistant for a chemical-processing client operating two plants (650+ employees), letting managers query worker performance and plant operations in natural language.
- Designed a multi-tool agent: a primary few-shot SQL tool (~100 pre-written CTEs stored with natural-language descriptions in a vector database, similarity-matched at query time and passed as few-shot examples to a SQL-writing LLM with schema context), an AWS OpenSearch vector-search fallback, and a graphing tool that produced charts directly from natural-language queries.
- Designed and implemented a bronze-silver-gold medallion pipeline on AWS: append-only event JSON landed via Lambda into a terabyte-scale bronze store, a Lambda-triggered silver layer maintaining active state and full history via Delta Lake, and a Glue job aggregating to production gold tables every five minutes.
- Deployed to real users with ~90% query accuracy by end of engagement.
- Stack: LlamaIndex, AWS OpenSearch, Streamlit, AWS Lambda, AWS Glue, Delta Lake, SQL.
2024.08 – 2025.01
AI Solutions Consultant (Contract)
Company: Chartwell Insurance Services
GitHub: ZachFara/Chartwell-Insurance-AI
- Built a production RAG-powered customer-service assistant for Chartwell's support team.
- The system ingested insurance policy documents, chunked and indexed them into Pinecone for semantic search, and retrieved context at query time to generate professional email-formatted responses.
- Built a dedicated hyperparameter-tuning harness that swept chunk size, overlap, top-k, and prompt variations against a question dataset with results logged across iterations, and experimented with alternative chunking strategies.
- Modular architecture separating agent orchestration, vector-store management, document loading, and configuration, with live document upload to keep the knowledge base current.
- Stack: GPT-4, Pinecone, Streamlit, LlamaParse.
2024.06 – 2024.08
Quantitative Analytics Intern
Company: Wells Fargo
- Worked on Fargo, Wells Fargo's production AI virtual assistant in the consumer banking app (245M+ interactions in 2024 across 33M+ mobile active users).
- Designed and ran a demographic bias-evaluation suite for Fargo's intent-classification model, systematically varying gendered pronouns and ethnicity references across hundreds of queries to measure output consistency, including edge cases where demographic context is legitimately relevant.
- Measured 90%+ classification consistency across demographic variations.
2023.06 – 2024.06
Data Scientist, Engineer I
Company: Badger Meter Inc.
- Built a large-scale AWS EMR + Spark ETL pipeline aggregating 5 TB of structured and unstructured telemetry from DynamoDB into a central warehouse, optimized with multithreading, parallel computing, and C++/Python interoperability.
- Engineered a gradient-boosting classifier to predict device failure from voltage telemetry on a highly imbalanced dataset with few labeled failures (~60% F1, a strong result given the signal and label constraints), plus a time-series regression model for voltage-degradation patterns.
- The model formed the basis of a proposed paid device-health API for out-of-warranty devices.
- Served as the sole quantitative source of truth for fleet health across a 1,000+ device pilot (path to a 3M+ device fleet), delivering monthly diagnostics to senior leadership.
- Stack: AWS EMR, Spark, DynamoDB, Python, C++, XGBoost, time-series modeling.
2020.08 – 2023.05
Data Science Researcher
Company: Marquette University
- Joined a CS research lab alongside PhD students (partially funded by NSF grant #1950826).
- First-authored and co-authored back-to-back IEEE Big Data publications (2022 and 2021) on hospital length-of-stay prediction from electronic health records, owning the full pipeline on the 2022 paper: data processing, modeling, Bayesian hyperparameter sweep, results, and analysis.
Teaching
2025.04 – present
Teaching Assistant, MS Applied Data Science
University: University of Chicago
- Selected by faculty to teach in the MS Applied Data Science program after completing my thesis under the same professor.
- TA for two courses: a robotics capstone (programmatic control of Tello drones via Python APIs, computer vision, and student thesis projects including a drone light show and drone painting) and Data Engineering (GCP, SQL, Snowflake, ETL/ELT, database design, OLAP vs. OLTP, star and snowflake schemas, slowly changing dimensions).
- Given creative latitude to develop and deliver lectures on topics including Git/GitHub, vibe coding, and Model Context Protocol.
Education
2023 – 2024
Master of Science, Applied Data Science
University: University of Chicago
- Coursework: Machine Learning, Natural Language Processing and Cognitive Computing, Time Series Analysis and Forecasting, MLOps, Data Engineering, Data Mining, Supply Chain Optimization, Linear and Non-Linear Modeling, Statistics, Linear Algebra.
- Thesis: Autonomous drone search using multimodal computer vision and large language models for zero-shot, open-vocabulary object identification (SkySearch).
2019 – 2023
Bachelor of Science, Mathematics and Computer Science
University: Marquette University
- Coursework: Calculus I–III, Linear Algebra, Real Analysis, Differential Equations, Probability and Statistics, Numerical Methods, Discrete Mathematics, Data Structures and Algorithms, Data Mining, Fundamentals of Artificial Intelligence, Database Systems, Software Engineering.
Selected Projects
SkySearch: Open-Vocabulary UAV Object Search (MS Thesis)
GitHub: ZachFara/SkySearch
- Multimodal LLM system for autonomous drone search that handles open-vocabulary and reasoning-based target descriptions, going beyond fixed-class detectors like YOLO (You Only Look Once).
- MLLM-agnostic architecture (tested GPT-4o, Gemini 1.5, Claude 3 Haiku) querying a 3×3×3 spatial grid to resolve target direction across left/right, up/down, and near/far axes.
- Built GLAD, a custom anti-contamination benchmark of 100 campus images with spatial annotations and paired negatives, to evaluate spatial localization on novel data.
- Live flights reached 95% success (90% true zero-shot, first attempt) across 20 courses, including abstract targets like "a book by Frank Herbert receiving a film adaptation" and "a textbook to prepare for a coding interview at Meta."
- Total live-flight inference cost under $1. Writeup available on GitHub.
- Stack: Python, OpenAI/Google/Anthropic APIs, DJI Tello SDK.
Concept Paths: Concept Geometry Interpretability
- Research toolkit for studying how semantic concepts (sentiment, concreteness) are geometrically encoded across transformer hidden layers in the GPT-2 and OPT families.
- Captures layerwise activations along concept axes and computes geometry metrics (PC1 explained variance, k-threshold dimensionality, subspace rotation), with permutation nulls and bootstrap controls, neuron-ablation dose-response curves, cross-concept subspace similarity, and a layerwise ridge-probe behavioral readout.
- Stack: Python, PyTorch, HuggingFace Transformers, nnsight.
Certifications
Skills
- Languages
- Python, R, SQL, JavaScript/TypeScript
- ML / AI
- PyTorch, TensorFlow/Keras, Scikit-learn, HuggingFace Transformers, XGBoost, Neural networks, Reinforcement learning, Computer vision, Bayesian hyperparameter optimization, SMOTE/oversampling, Time-series modeling, Model validation
- LLM / Agentic
- RAG design and tuning, Agentic system design (tool registries, orchestration), Memory management, MLLM evaluation and benchmarking, Few-shot prompting, LlamaIndex, AWS Bedrock, OpenAI / Anthropic / Google Cloud Model Garden APIs
- Data Engineering & Cloud
- Apache Spark (AWS EMR), AWS Lambda, AWS Glue, S3, Delta Lake/Parquet, DynamoDB, Pinecone, AWS OpenSearch, Medallion architecture, Snowflake, GCP/BigQuery, ETL design
- Interpretability
- Activation analysis, Concept-geometry/subspace analysis, Ablation studies, Behavioral readout
- Dev Tools
- Git/GitHub, Docker, Weights & Biases, Streamlit, Dev Containers, pytest