diff --git a/.gitignore b/.gitignore
index 6de8849a..a13d13c3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,4 +9,5 @@ google_jetstream.egg-info/
 data/
 logs/
 tmp/
-venv/
\ No newline at end of file
+venv/
+.vscode/
diff --git a/jetstream/core/orchestrator.py b/jetstream/core/orchestrator.py
index 8b5268e5..34b45d8e 100644
--- a/jetstream/core/orchestrator.py
+++ b/jetstream/core/orchestrator.py
@@ -93,8 +93,9 @@
 from jetstream.core.proto import jetstream_pb2_grpc
 from jetstream.core.utils import async_multifuture
 from jetstream.engine import engine_api
-import numpy as np
 
+import numpy as np
+import prometheus_client
 
 root = logging.getLogger()
 root.setLevel(logging.DEBUG)
@@ -209,6 +210,9 @@ class Driver:
   # todo: remove jax_padding after all then engine migrate to np padding
   _jax_padding = True
 
+  # Record metrics for prefill_backlog size
+  _prefill_backlog_size_metric: prometheus_client.Gauge
+
   def __init__(
       self,
       prefill_engines: Optional[list[engine_api.Engine]] = None,
@@ -242,6 +246,10 @@ def __init__(
     # Stage 1
     # At first, a request is placed here in order to get prefilled.
     self._prefill_backlog = queue.Queue()
+    self._prefill_backlog_size_metric = prometheus_client.Gauge(
+        "jetstream_prefill_backlog_size", "Size of prefill queue"
+    )
+
     # Stage 2
     # After prefilling, it is placed here in order to get transferred to
     # one of the generate backlogs.
@@ -421,6 +429,7 @@ def place_request_on_prefill_queue(self, request: ActiveRequest):
     """Used to place new requests for prefilling and generation."""
     # Don't block so we can fail and shed load when the queue is full.
     self._prefill_backlog.put(request, block=False)
+    self._prefill_backlog_size_metric.set(self._prefill_backlog.qsize())
 
   def _load_cache_history(self, path: str) -> Union[None, Any]:
     """Loads previous kv cache for a longer conversation."""
@@ -442,6 +451,8 @@ def _prefill_thread(self, idx: int):
       my_transfer_backlog = self._transfer_backlogs[idx]
       # The prefill thread can just sleep until it has work to do.
       request = self._prefill_backlog.get(block=True)
+      self._prefill_backlog_size_metric.set(self._prefill_backlog.qsize())
+
       if request is None:
         break
       # Tokenize, and introduce a leading dimension
diff --git a/jetstream/core/server_lib.py b/jetstream/core/server_lib.py
index d66af518..cc983535 100644
--- a/jetstream/core/server_lib.py
+++ b/jetstream/core/server_lib.py
@@ -20,6 +20,7 @@
 import asyncio
 from concurrent import futures
 import logging
+import os
 import threading
 from typing import Any, Type
 
@@ -29,8 +30,14 @@
 from jetstream.core import orchestrator
 from jetstream.core.proto import jetstream_pb2_grpc
 
+from prometheus_client import start_http_server
 
 _HOST = "[::]"
+PROMETHEUS_ENABLED_ON_PORT = (
+    int(os.getenv("PROMETHEUS_ENABLED_ON_PORT"))
+    if os.getenv("PROMETHEUS_ENABLED_ON_PORT")
+    else None
+)
 
 
 class JetStreamServer:
@@ -130,6 +137,17 @@ def run(
   logging.info("Starting server on port %d with %d threads", port, threads)
 
   jetstream_server.start()
+
+  # Setup Prometheus server
+  if PROMETHEUS_ENABLED_ON_PORT is not None:
+    logging.info(
+        "Starting Prometheus server on port %d", PROMETHEUS_ENABLED_ON_PORT
+    )
+    start_http_server(PROMETHEUS_ENABLED_ON_PORT)
+  else:
+    logging.info(
+        "Not starting Prometheus server: PROMETHEUS_ENABLED_ON_PORT not set"
+    )
   return jetstream_server
 
 
diff --git a/requirements.in b/requirements.in
index bc5ba8fc..6f4ebb60 100644
--- a/requirements.in
+++ b/requirements.in
@@ -6,7 +6,8 @@ jax
 jaxlib
 numpy
 portpicker
+prometheus-client
 pytest
 seqio
 tiktoken
-blobfile
\ No newline at end of file
+blobfile
diff --git a/requirements.txt b/requirements.txt
index 20029e10..f2a23c7b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -177,6 +177,8 @@ pluggy==1.4.0
     # via pytest
 portpicker==1.6.0
     # via -r requirements.in
+prometheus-client==0.20.0
+    # via -r requirements.in
 promise==2.3
     # via tfds-nightly
 protobuf==3.20.3