Work that ships

End-to-end machine learning pipeline that ingests a 87k-row loan dataset, runs full preprocessing (missing values, encoding, scaling), trains a Random Forest classifier, and serves predictions via a FastAPI REST endpoint. Every prediction is logged to SQLite for auditing.

• ▹Handled class imbalance with SMOTE oversampling — lifted recall on minority class from 61% to 89%.
• ▹Implemented feature importance ranking; top predictors were credit_history, loan_amount_term, and applicant_income.
• ▹Built FastAPI endpoint with Pydantic validation, JSON responses, and per-request SQLite audit logging.
• ▹Packaged with requirements.txt and documented with clear README for reproducibility.

Large-scale data infrastructure for Korean local governments — aggregating GIS data, population census records, budget databases, and IoT sensor feeds into a unified PostgreSQL warehouse. Powers real-time dashboards used by city planners and government officials for data-driven policy decisions.

• ▹Designed ETL pipelines from 4+ heterogeneous sources including GIS shapefiles, CSV census exports, and SQL dumps.
• ▹Implemented deduplication, null-fill strategies, and data quality validation gates before warehouse load.
• ▹Built REST API layer on top of the warehouse to serve dashboard data to a Next.js frontend.
• ▹Maintained schema versioning using Prisma migrations to handle evolving government data requirements.
• ▹Delivered dashboards enabling geographic and temporal analysis of municipal resource allocation.

This website — a fully bilingual (EN/KR) portfolio and contact system built with Next.js 15 App Router, Prisma ORM, and PostgreSQL. Features a contact form with email delivery via Resend, a public Q&A system with rate limiting, and a filterable resume page.

• ▹Built with Next.js 15 App Router — server components, nested layouts, locale-prefixed routing (/en, /ko).
• ▹Contact form POSTs to a serverless API route that stores in PostgreSQL via Prisma and sends email via Resend.
• ▹Public Q&A system with IP-based rate limiting (3 questions / 10 min) and honeypot anti-spam.
• ▹Filterable resume section with tag-based project/experience filtering and skills evidence mapping.
• ▹Dark mode support via CSS custom properties and `prefers-color-scheme` media query.