Diya Vij

Berkeley, CA · diyavij@berkeley.edu · LinkedIn · GitHub

Education

University of California, Berkeley

May 2026

Bachelors in Applied Mathematics & Statistics; Minor in Data Science

Relevant coursework: Machine Learning, Bayesian Statistics, Time Series, Regression Analysis, Game Theory, Data Structures & Algorithms, Stochastic Processes, Data and AI Ethics

Experience

Marketing Lead & Internal Vice President — Cal Hacks · Hackathons @ Berkeley

Aug 2024 – present
  • Direct operations and marketing for Cal Hacks, the world's largest collegiate hackathon, and the UC Berkeley AI Hackathon; oversee a $1,250,000+ annual budget and 30+ organizers across logistics, sponsorships, and outreach.
  • Scaled the applicant pipeline to 25,000+ registrants and 4,000+ hackers per cycle by owning top-of-funnel growth across channels; managed 50+ sponsor partners including Anthropic, Google, and Amazon.
  • Designed and launched the org's first short-form video program (Instagram Reels + TikTok), personally producing the content that drove a step-change in reach and grew Instagram from 4,000 to 6,000+ followers.
  • Piloted the organization's first Meta (Facebook/Instagram) paid-ads campaign, building the acquisition funnel from scratch.

Data Science & Machine Learning Intern — Regeneron Pharmaceuticals, Tarrytown, NY

Summer 2025
  • Shipped a two-path RAG pipeline (semantic vector search + keyword retrieval over PubMed, ClinicalTrials.gov, and UK Biobank) that turned a multi-day research task into a minutes-long query for a department of 50+ researchers.
  • Engineered 600+ features from time-series data across 500+ patients and trained an XGBoost model reaching 85%+ accuracy detecting disease-severity progression; presented to medical directors and at a 150+ person symposium.

Data Services Intern — University of California, Office of Information Technology

Spring – Fall 2024
  • Refactored SSIS ETL pipelines into Python and built Power BI dashboards for Facilities Financial Services, improving data-driven reporting across university IT systems.

Projects

Reasoning-Audit Agent · Claude API (agentic tool-use), FastAPI, SSE, Pydantic, Hugging Face Datasets, Railway

2026
  • Built a multi-step agent (hand-rolled Claude tool-use loop, no framework) that reconstructs an argument's premise structure — including unstated "suppressed" premises — and separates genuine logical failures from the acceptable compression every real argument uses, grounding each flag in cited text and routing low-confidence calls to a human reviewer.
  • Shipped a two-layer evaluation harness — academic fallacy benchmark (LOGIC/LOGICCLIMATE) for breadth + a hand-labeled set for depth — scoring detection recall, false-positive rate, evidence grounding, and confidence calibration (ECE/Brier); live token-streaming demo (SSE), deploying on Railway.

Journal · React Native, Supabase, pgvector, Claude API

2025 – present
  • Built a mobile-first AI journaling app: entries embedded via nomic-embed-text (pgvector), retrieved via hybrid semantic + recency scoring, queried through Claude Sonnet; a Supabase cron autonomously runs weekly synthesis via the Claude API.

Roseyflow · React, Express, PostgreSQL, Bayesian ML, Twilio API

2025 – present
  • Built a menstrual-cycle mood tracker powered by a Bayesian model trained on the mcPHASES wearable dataset (PhysioNet); personalizes predictions as users log data and sends cycle insights via Twilio SMS.

Sleep Apnea Detection — CNN–Transformer · TensorFlow, Signal Processing

Fall 2025
  • Co-built a CNN–Transformer hybrid classifying sleep apnea from 150 GB of multimodal EEG/ECG data (DREAMT), achieving 78% accuracy and 0.86 ROC-AUC across 4 model architectures.

Skills

Engineering: Python, JavaScript/TypeScript, React, React Native, Express, Flask, FastAPI, PostgreSQL, REST APIs, SSE streaming

Data & ML: Pandas, NumPy, Scikit-learn, XGBoost, TensorFlow, LangChain, RAG, agentic tool-use / agent loops, LLM evaluation, model calibration (ECE/Brier), Bayesian modeling, Power BI, Tableau

Growth & analytics: Funnel & cohort analysis, A/B experimentation, SQL, paid social (Meta Ads), short-form content production, social channel growth, team management, event budgeting and management

Hackathon awards: BayHacks 2021 (Winner); Best Use of Twilio — AthenaHacks 2023; LAHacks; TreeHacks

Leadership & extracurriculars

Officer — Mathematics Undergraduate Student Association (MUSA)

Aug 2024 – present
  • Berkeley Math Equity & Inclusion Committee rep.

Student Consultant — University of California Information Technology

Aug 2023 – present
  • Part-time (10–20 hours/week) IT support for users at UC Facilities and UC Berkeley Haas.

Director of Operations — Data Science Club

May 2023 – Aug 2024
  • Managed club operations and alumni relations.