A production-grade Node backend for a dApp typically layers several of this track's topics: an Express-style API with validated routes (topics 25-27), configuration driven by environment variables per chain (topics 7, 24, 44), an indexer polling or subscribing to chain data into a database (topics 29-30, 43), caching for hot reads (topic 33), structured logging and health checks (topics 28, 46), and graceful shutdown plus retry/backoff around every external call (topics 32, 35).
js
async function main() {
const config = loadConfig(); // fail fast if misconfigured
const db = await connectDb(config.databaseUrl);
const app = buildApp({ db, config });
const server = app.listen(config.port);
startIndexer({ db, rpcUrl: config.rpcUrl }).catch((err) => log("error", "indexer crashed", { err: err.message }));
process.on("SIGTERM", async () => {
server.close();
await db.close();
process.exit(0);
});
}
main().catch((err) => { console.error("fatal startup error:", err); process.exit(1); });None of these pieces is exotic in isolation — the skill this capstone tests is composing them into a service that stays correct and observable under real network conditions: slow RPC nodes, restarts, and traffic spikes.