Real-Time Trading Event Feed Dashboard (React)

Build a React dashboard that subscribes to a supplied stream of trade and quote events. Render newest-first feeds by event type, maintain summary statistics over the most recent 30 seconds, and support pause/resume with an explicit explanation of resume behavior; styling is out of scope and AI assistance is disallowed. Requirements Use React and subscribe to the supplied stream function; the stream provider itself does not need to be implemented. Each event has the following shape: { id, timestamp, tradeType, side, size, price, bid, ask, askSize, bidSize } Display incoming events with the newest event first and separate the display by trade type. The prompt examples name quote and sell sections. Display summary statistics over the most recent 30 seconds. Once an event is older than 30 seconds, it must no longer contribute to the summary. Add pause and resume controls. Pausing stops dashboard data updates; resuming continues them, and the candidate must explain the chosen resume behavior. Notes Keep subscription setup and cleanup in an effect, and route each callback through a reducer or functional state update so rapid events do not read a stale render snapshot. For the 30-second summary, keep timestamp-ordered active events and evict expired entries while updating the corresponding aggregates. Use a periodic clock tick as well as arrival-time eviction so an event expires even when the stream is temporarily quiet. Styling is explicitly out of scope. AI assistance is explicitly disallowed. Clarify the event-bucket taxonomy before coding because the supplied examples mix a quote event type with a sell-side label. State whether resume applies buffered events or resumes from the current stream position; the interviewer asks for the semantics to be explained rather than prescribing one behavior. Preparation Build a small React prototype around a mock subscription callback, bucket the events for display, and keep each bucket newest-first. Drill a time-windowed summary with pause/resume controls, writing down the chosen resume semantics before coding.