MixedScheduler microtasks blocking Node.js I/O?Stream.mapEffect pipeline (~8,000+ elements/sec from a WebSocket). We use Node.js ws + createWebSocketStream + Stream.fromAsyncIterable so that backpressure propagates back to TCP (the server respects it). The stream decodes events and writes some to Postgres (~100ms RTT).sql.execute taking 2-4s despite <1ms server-side execution. A raw pool.query("SELECT 1") probe in the same process showed the same latency — ruling out Effect SQL, Drizzle, connection pooling, etc.MixedScheduler scheduling fiber continuations via Promise.resolve().then(). At high throughput the microtask queue stays full, preventing Node.js from reaching the I/O poll phase where TCP callbacks (DB responses) fire. The setTimeout(0) fallback every 2048 scheduler cycles seems too infrequent at our volume.setImmediate scheduler resolved it:withMaxOpsBeforeYield can tune the tradeoff.