1. Open bare repo at /mnt/efs/{user}/{wiki}/repo.git
2. Commit page change
-
3. If semantic search enabled: enqueue SQS message for reindex
+
3. Write reindex record to DynamoDB ReindexQueue table
+
(triggers embedding Lambda via DynamoDB Streams — see Semantic Search section)
```
**Concurrency**: NFS handles file-level locking natively. Git's own locking (`index.lock`) works correctly on NFS. Concurrent reads are unlimited. Concurrent writes to the same repo are serialized by git's lock file. No application-level locking needed.