Backend systems, agents, and the evaluation harnesses behind them.
An agentic RAG system for macOS troubleshooting — a branching LangGraph, a domain knowledge base built from 9 scrapers, and a blind-judge evaluation harness that blocks its own deploys on quality regressions.
A coding agent built on LangGraph from scratch — a planner, a ReAct tool loop, and a network-disabled Docker sandbox — graded against 50 real Django and Sphinx issues from SWE-bench Verified Mini.
A Spring Boot REST API for personal finance tracking, with a security layer that returns proper 401/403 JSON instead of Spring's default HTML redirects, and JPA projections that push aggregation into SQL.
A digital wallet decomposed into four Spring Boot services communicating over Kafka, with per-service data ownership and dedicated consumer groups for wallet-creation and transaction-update events.
A hand-rolled reliability layer over raw UDP sockets in C — sequence numbering, acknowledgements, gap detection, and retransmission — built to understand what TCP does by implementing a subset of it.
The portfolio itself — an MDX content pipeline validated by Zod at build time, and a single shared WebGL canvas that's capability-gated and never blocks first paint.