Overview
Fantasy basketball managers make a steady stream of small decisions: which player to pick up, which trade to accept, who to drop. Lightning is an agent that looks at the live state of a Yahoo Fantasy league and gives recommendations for those decisions.
What I built
- Agent. A LangGraph agent using Claude that reasons over live Yahoo Fantasy data to recommend trades and waiver pickups.
- Backend. FastAPI service with Postgres for persistence.
- Interface. A React app with a chat view, a dashboard and a trade analyzer.
- Evaluation. LangSmith evals used as a quality gate before each release.
Design choices
I built the product end to end, from the agent to the deployed UI. Evals run before each release, so changes to prompts and tools are checked against a fixed set of cases before they reach users.
NEXT · 02
Intent Analysis System →