How to Build a Resilient Live Sports Odds Feed Using SSE and Snapshot APIs

Maintaining a live sports odds display requires two steps: loading an accurate initial state via a REST snapshot and keeping it updated through a Server-Sent Events stream. Developers must use the same market filters on both the snapshot and stream endpoints to ensure consistency between the starting data and incoming changes. The SSE stream emits three message types — delta, heartbeat, and resync — each requiring a distinct response, including full snapshot reloads when a resync is received. To avoid data loss on crashes, the resume cursor and updated state must always be saved together atomically, never in separate steps. On disconnection, clients should reconnect using the last valid cursor with catchup mode enabled and apply jittered exponential backoff to avoid overloading the server.