Nice work! The real-time vehicle movement rendering challenge you mentioned reminded me of a tool I've been building — Moveet (https://github.com/ivannovazzi/moveet), an open-source fleet simulator that drives synthetic vehicles on real OSM road networks using A* pathfinding, streaming positions over WebSocket. It's aimed at developers who need realistic GPS movement data to test fleet or logistics software, and supports Kafka, Redis, and REST sinks. Your approach of batching 30k+ GeoJSON features into typed arrays is a great pattern for this kind of workload.