diff --git a/crates/milli/src/update/new/indexer/write.rs b/crates/milli/src/update/new/indexer/write.rs
index fc647cfa5..f910d2e7f 100644
--- a/crates/milli/src/update/new/indexer/write.rs
+++ b/crates/milli/src/update/new/indexer/write.rs
@@ -71,7 +71,19 @@ pub(super) fn write_to_db(
             &mut aligned_embedding,
         )?;
     }
+
     write_from_bbqueue(&mut writer_receiver, index, wtxn, arroy_writers, &mut aligned_embedding)?;
+
+    let direct_attempts = writer_receiver.sent_messages_attempts();
+    let blocking_attempts = writer_receiver.blocking_sent_messages_attempts();
+    let congestion_pct = (blocking_attempts as f64 / direct_attempts as f64) * 100.0;
+    tracing::debug!(
+        "Channel congestion metrics - \
+        Direct send attempts: {direct_attempts}, \
+        Blocking send attempts: {blocking_attempts} \
+        ({congestion_pct:.1}% congestion)"
+    );
+
     Ok(())
 }