diff --git a/lerobot/common/policies/sac/modeling_sac.py b/lerobot/common/policies/sac/modeling_sac.py
index 84ff60816..c9024cd84 100644
--- a/lerobot/common/policies/sac/modeling_sac.py
+++ b/lerobot/common/policies/sac/modeling_sac.py
@@ -78,6 +78,7 @@ class SACPolicy(
         # NOTE: For images the encoder should be shared between the actor and critic
         if config.shared_encoder:
             encoder_critic = SACObservationEncoder(config, self.normalize_inputs)
+            encoder_critic = torch.compile(encoder_critic)
             encoder_actor: SACObservationEncoder = encoder_critic
         else:
             encoder_critic = SACObservationEncoder(config, self.normalize_inputs)
@@ -96,6 +97,7 @@ class SACPolicy(
             ),
             output_normalization=self.normalize_targets,
         )
+        self.critic_ensemble = torch.compile(self.critic_ensemble)
 
         self.critic_target = CriticEnsemble(
             encoder=encoder_critic,
@@ -110,6 +112,7 @@ class SACPolicy(
             ),
             output_normalization=self.normalize_targets,
         )
+        self.critic_target = torch.compile(self.critic_target)
 
         self.critic_target.load_state_dict(self.critic_ensemble.state_dict())
 
@@ -120,6 +123,9 @@ class SACPolicy(
             encoder_is_shared=config.shared_encoder,
             **config.policy_kwargs,
         )
+
+        # self.actor = torch.compile(self.actor)
+
         if config.target_entropy is None:
             config.target_entropy = -np.prod(config.output_shapes["action"][0]) / 2  # (-dim(A)/2)
 
@@ -148,7 +154,7 @@ class SACPolicy(
         return actions
 
     def critic_forward(
-        self, observations: dict[str, Tensor], actions: Tensor, use_target: bool = False
+        self, observations: dict[str, Tensor], actions: Tensor, use_target: bool = False, image_features: Tensor | None = None
     ) -> Tensor:
         """Forward pass through a critic network ensemble
 
@@ -161,7 +167,7 @@ class SACPolicy(
             Tensor of Q-values from all critics
         """
         critics = self.critic_target if use_target else self.critic_ensemble
-        q_values = critics(observations, actions)
+        q_values = critics(observations, actions, image_features=image_features)
         return q_values
 
     def forward(self, batch: dict[str, Tensor]) -> dict[str, Tensor | float]: ...
@@ -175,14 +181,14 @@ class SACPolicy(
                 + target_param.data * (1.0 - self.config.critic_target_update_weight)
             )
 
-    def compute_loss_critic(self, observations, actions, rewards, next_observations, done) -> Tensor:
+    def compute_loss_critic(self, observations, actions, rewards, next_observations, done, image_features: Tensor | None = None, next_image_features: Tensor | None = None) -> Tensor:
         temperature = self.log_alpha.exp().item()
         with torch.no_grad():
-            next_action_preds, next_log_probs, _ = self.actor(next_observations)
+            next_action_preds, next_log_probs, _ = self.actor(next_observations, next_image_features)
 
             # 2- compute q targets
             q_targets = self.critic_forward(
-                observations=next_observations, actions=next_action_preds, use_target=True
+                observations=next_observations, actions=next_action_preds, use_target=True, image_features=next_image_features
             )
 
             # subsample critics to prevent overfitting if use high UTD (update to date)
@@ -214,18 +220,18 @@ class SACPolicy(
         ).sum()
         return critics_loss
 
-    def compute_loss_temperature(self, observations) -> Tensor:
+    def compute_loss_temperature(self, observations, image_features: Tensor | None = None) -> Tensor:
         """Compute the temperature loss"""
         # calculate temperature loss
         with torch.no_grad():
-            _, log_probs, _ = self.actor(observations)
+            _, log_probs, _ = self.actor(observations, image_features)
         temperature_loss = (-self.log_alpha.exp() * (log_probs + self.config.target_entropy)).mean()
         return temperature_loss
 
-    def compute_loss_actor(self, observations) -> Tensor:
+    def compute_loss_actor(self, observations, image_features: Tensor | None = None) -> Tensor:
         temperature = self.log_alpha.exp().item()
 
-        actions_pi, log_probs, _ = self.actor(observations)
+        actions_pi, log_probs, _ = self.actor(observations, image_features)
 
         q_preds = self.critic_forward(observations, actions_pi, use_target=False)
         min_q_preds = q_preds.min(dim=0)[0]
@@ -360,6 +366,7 @@ class CriticEnsemble(nn.Module):
         self,
         observations: dict[str, torch.Tensor],
         actions: torch.Tensor,
+        image_features: torch.Tensor | None = None,
     ) -> torch.Tensor:
         device = get_device_from_parameters(self)
         # Move each tensor in observations to device
@@ -370,7 +377,7 @@ class CriticEnsemble(nn.Module):
         actions = self.output_normalization(actions)["action"]
         actions = actions.to(device)
 
-        obs_enc = observations if self.encoder is None else self.encoder(observations)
+        obs_enc = image_features if image_features is not None else (observations if self.encoder is None else self.encoder(observations))
 
         inputs = torch.cat([obs_enc, actions], dim=-1)
         list_q_values = []
@@ -435,9 +442,10 @@ class Policy(nn.Module):
     def forward(
         self,
         observations: torch.Tensor,
+        image_features: torch.Tensor | None = None,
     ) -> Tuple[torch.Tensor, torch.Tensor]:
         # Encode observations if encoder exists
-        obs_enc = observations if self.encoder is None else self.encoder(observations)
+        obs_enc = image_features if image_features is not None else (observations if self.encoder is None else self.encoder(observations))
 
         # Get network outputs
         outputs = self.network(obs_enc)
diff --git a/lerobot/configs/policy/sac_maniskill.yaml b/lerobot/configs/policy/sac_maniskill.yaml
index 3edf7d67a..23e96c2e9 100644
--- a/lerobot/configs/policy/sac_maniskill.yaml
+++ b/lerobot/configs/policy/sac_maniskill.yaml
@@ -31,7 +31,7 @@ training:
   online_env_seed: 10000
   online_buffer_capacity: 1000000
   online_buffer_seed_size: 0
-  online_step_before_learning: 5000
+  online_step_before_learning: 500
   do_online_rollout_async: false
   policy_update_freq: 1
 
@@ -52,10 +52,10 @@ policy:
   n_action_steps: 1
 
   shared_encoder: true
-  vision_encoder_name: null
-  # vision_encoder_name: "helper2424/resnet10"
-  # freeze_vision_encoder: true
-  freeze_vision_encoder: false
+  # vision_encoder_name: null
+  vision_encoder_name: "helper2424/resnet10"
+  freeze_vision_encoder: true
+  # freeze_vision_encoder: false
   input_shapes:
     # # TODO(rcadene, alexander-soare): add variables for height and width from the dataset/env?
     observation.state: ["${env.state_dim}"]
diff --git a/lerobot/scripts/server/buffer.py b/lerobot/scripts/server/buffer.py
index 6a290e6e9..c52e9c06d 100644
--- a/lerobot/scripts/server/buffer.py
+++ b/lerobot/scripts/server/buffer.py
@@ -19,6 +19,7 @@ from typing import Any, Callable, Optional, Sequence, TypedDict
 
 import torch
 import torch.nn.functional as F  # noqa: N812
+import multiprocessing
 from tqdm import tqdm
 
 from lerobot.common.datasets.lerobot_dataset import LeRobotDataset
@@ -135,10 +136,11 @@ class ReplayBuffer:
         self,
         capacity: int,
         device: str = "cuda:0",
-        state_keys: Optional[Sequence[str]] = None,
+        state_keys: Optional[list[str]] = None,
         image_augmentation_function: Optional[Callable] = None,
         use_drq: bool = True,
         storage_device: str = "cpu",
+        use_shared_memory: bool = False,
     ):
         """
         Args:
@@ -150,16 +152,17 @@ class ReplayBuffer:
             use_drq (bool): Whether to use the default DRQ image augmentation style, when sampling in the buffer.
             storage_device: The device (e.g. "cpu" or "cuda:0") where the data will be stored when adding transitions to the buffer.
                 Using "cpu" can help save GPU memory.
+            use_shared_memory (bool): Whether to use shared memory for the buffer.
         """
         self.capacity = capacity
         self.device = device
         self.storage_device = storage_device
-        self.memory: list[Transition] = []
+        self.memory: list[Transition] = torch.multiprocessing.Manager().list() if use_shared_memory else []
         self.position = 0
 
-        # If no state_keys provided, default to an empty list
-        # (you can handle this differently if needed)
-        self.state_keys = state_keys if state_keys is not None else []
+        # Convert state_keys to a list for pickling
+        self.state_keys = list(state_keys) if state_keys is not None else []
+
         if image_augmentation_function is None:
             self.image_augmentation_function = functools.partial(random_shift, pad=4)
         self.use_drq = use_drq
@@ -187,7 +190,7 @@ class ReplayBuffer:
         #     }
 
         if len(self.memory) < self.capacity:
-            self.memory.append(None)
+            self.memory.append({})  # Need to append something first for Manager().list()
 
         # Create and store the Transition
         self.memory[self.position] = Transition(
@@ -210,6 +213,7 @@ class ReplayBuffer:
         capacity: Optional[int] = None,
         action_mask: Optional[Sequence[int]] = None,
         action_delta: Optional[float] = None,
+        use_shared_memory: bool = False,
     ) -> "ReplayBuffer":
         """
         Convert a LeRobotDataset into a ReplayBuffer.
@@ -233,7 +237,7 @@ class ReplayBuffer:
                 "The capacity of the ReplayBuffer must be greater than or equal to the length of the LeRobotDataset."
             )
 
-        replay_buffer = cls(capacity=capacity, device=device, state_keys=state_keys)
+        replay_buffer = cls(capacity=capacity, device=device, state_keys=state_keys, use_shared_memory=use_shared_memory)
         list_transition = cls._lerobotdataset_to_transitions(dataset=lerobot_dataset, state_keys=state_keys)
         # Fill the replay buffer with the lerobot dataset transitions
         for data in list_transition:
@@ -345,7 +349,19 @@ class ReplayBuffer:
     def sample(self, batch_size: int) -> BatchTransition:
         """Sample a random batch of transitions and collate them into batched tensors."""
         batch_size = min(batch_size, len(self.memory))
-        list_of_transitions = random.sample(self.memory, batch_size)
+        # Different sampling approach for shared memory list vs regular list
+
+        list_of_transitions = random.sample(list(self.memory), batch_size)
+        # if isinstance(self.memory, multiprocessing.managers.ListProxy):
+        #     # For shared memory list, we need to be careful about thread safety
+        #     with torch.multiprocessing.Lock():
+        #         # Get indices first to minimize lock time
+        #         indices = torch.randint(len(self.memory), size=(batch_size,)).tolist()
+        #         # Convert to list to avoid multiple proxy accesses
+        #         list_of_transitions = [self.memory[i] for i in indices]
+        # else:
+        #     # For regular list, use faster random.sample
+        #     list_of_transitions = random.sample(self.memory, batch_size)
 
         # -- Build batched states --
         batch_state = {}
diff --git a/lerobot/scripts/server/learner_server.py b/lerobot/scripts/server/learner_server.py
index 3a608538c..96f817a8d 100644
--- a/lerobot/scripts/server/learner_server.py
+++ b/lerobot/scripts/server/learner_server.py
@@ -36,6 +36,9 @@ from termcolor import colored
 from torch import nn
 from torch.optim.optimizer import Optimizer
 
+# For profiling only
+import datetime
+
 from lerobot.common.datasets.factory import make_dataset
 
 # TODO: Remove the import of maniskill
@@ -262,15 +265,15 @@ def learner_push_parameters(
     while True:
         with policy_lock:
             params_dict = policy.actor.state_dict()
-            if policy.config.vision_encoder_name is not None:
-                if policy.config.freeze_vision_encoder:
-                    params_dict: dict[str, torch.Tensor] = {
-                        k: v for k, v in params_dict.items() if not k.startswith("encoder.")
-                    }
-                else:
-                    raise NotImplementedError(
-                        "Vision encoder is not frozen, we need to send the full model over the network which requires chunking the model."
-                    )
+            # if policy.config.vision_encoder_name is not None:
+            #     if policy.config.freeze_vision_encoder:
+            #         params_dict: dict[str, torch.Tensor] = {
+            #             k: v for k, v in params_dict.items() if not k.startswith("encoder.")
+            #         }
+            #     else:
+            #         raise NotImplementedError(
+            #             "Vision encoder is not frozen, we need to send the full model over the network which requires chunking the model."
+            #         )
 
         params_dict = move_state_dict_to_device(params_dict, device="cpu")
         # Serialize
@@ -347,6 +350,7 @@ def add_actor_information_and_train(
     interaction_message, transition = None, None
     optimization_step = resume_optimization_step if resume_optimization_step is not None else 0
     interaction_step_shift = resume_interaction_step if resume_interaction_step is not None else 0
+
     while True:
         while not transition_queue.empty():
             transition_list = transition_queue.get()
@@ -370,6 +374,7 @@ def add_actor_information_and_train(
         # logging.info(f"Size of replay buffer: {len(replay_buffer)}")
         # logging.info(f"Size of offline replay buffer: {len(offline_replay_buffer)}")
 
+        image_features, next_image_features = None, None
         time_for_one_optimization_step = time.time()
         for _ in range(cfg.policy.utd_ratio - 1):
             batch = replay_buffer.sample(batch_size)
@@ -385,6 +390,21 @@ def add_actor_information_and_train(
             done = batch["done"]
             check_nan_in_transition(observations=observations, actions=actions, next_state=next_observations)
 
+            # Precompute encoder features from the frozen vision encoder if enabled
+            with record_function("encoder_forward"):
+                if policy.config.vision_encoder_name is not None and policy.config.freeze_vision_encoder:
+                    with torch.no_grad():
+                        image_features = (
+                            policy.actor.encoder(observations)
+                            if policy.actor.encoder is not None
+                            else None
+                        )
+                        next_image_features = (
+                            policy.actor.encoder(next_observations)
+                            if policy.actor.encoder is not None
+                            else None
+                        )
+
             with policy_lock:
                 loss_critic = policy.compute_loss_critic(
                     observations=observations,
@@ -392,6 +412,8 @@ def add_actor_information_and_train(
                     rewards=rewards,
                     next_observations=next_observations,
                     done=done,
+                    image_features=image_features,
+                    next_image_features=next_image_features,
                 )
                 optimizers["critic"].zero_grad()
                 loss_critic.backward()
@@ -413,6 +435,19 @@ def add_actor_information_and_train(
 
         check_nan_in_transition(observations=observations, actions=actions, next_state=next_observations)
 
+        # Precompute encoder features from the frozen vision encoder if enabled
+        if policy.config.vision_encoder_name is not None and policy.config.freeze_vision_encoder:
+            with torch.no_grad():
+                image_features = (
+                    policy.actor.encoder(observations)
+                    if policy.actor.encoder is not None
+                    else None
+                )
+                next_image_features = (
+                    policy.actor.encoder(next_observations)
+                    if policy.actor.encoder is not None
+                    else None
+                )
         with policy_lock:
             loss_critic = policy.compute_loss_critic(
                 observations=observations,
@@ -420,6 +455,8 @@ def add_actor_information_and_train(
                 rewards=rewards,
                 next_observations=next_observations,
                 done=done,
+                image_features=image_features,
+                next_image_features=next_image_features,
             )
             optimizers["critic"].zero_grad()
             loss_critic.backward()
@@ -431,7 +468,7 @@ def add_actor_information_and_train(
         if optimization_step % cfg.training.policy_update_freq == 0:
             for _ in range(cfg.training.policy_update_freq):
                 with policy_lock:
-                    loss_actor = policy.compute_loss_actor(observations=observations)
+                    loss_actor = policy.compute_loss_actor(observations=observations, image_features=image_features)
 
                     optimizers["actor"].zero_grad()
                     loss_actor.backward()
@@ -439,7 +476,7 @@ def add_actor_information_and_train(
 
                     training_infos["loss_actor"] = loss_actor.item()
 
-                    loss_temperature = policy.compute_loss_temperature(observations=observations)
+                    loss_temperature = policy.compute_loss_temperature(observations=observations, image_features=image_features)
                     optimizers["temperature"].zero_grad()
                     loss_temperature.backward()
                     optimizers["temperature"].step()
@@ -503,6 +540,12 @@ def add_actor_information_and_train(
 
             logging.info("Resume training")
 
+        profiler.step()
+        
+        if optimization_step >= 50:  # Profile for 500 steps
+            profiler.stop()
+            break
+
 
 def make_optimizers_and_scheduler(cfg, policy: nn.Module):
     """
@@ -583,7 +626,7 @@ def train(cfg: DictConfig, out_dir: str | None = None, job_name: str | None = No
         pretrained_policy_name_or_path=str(logger.last_pretrained_model_dir) if cfg.resume else None,
     )
     # compile policy
-    policy = torch.compile(policy)
+    # policy = torch.compile(policy)
     assert isinstance(policy, nn.Module)
 
     optimizers, lr_scheduler = make_optimizers_and_scheduler(cfg, policy)
diff --git a/lerobot/scripts/server/learner_server_mp.py b/lerobot/scripts/server/learner_server_mp.py
new file mode 100644
index 000000000..369219cbc
--- /dev/null
+++ b/lerobot/scripts/server/learner_server_mp.py
@@ -0,0 +1,767 @@
+#!/usr/bin/env python
+
+# Copyright 2024 The HuggingFace Inc. team.
+# All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import io
+import logging
+import pickle
+import queue
+import shutil
+import time
+from pprint import pformat
+from multiprocessing import Process, Event
+from torch.multiprocessing import Queue, Lock, set_start_method
+import logging.handlers
+from pathlib import Path
+
+import grpc
+
+# Import generated stubs
+import hilserl_pb2  # type: ignore
+import hilserl_pb2_grpc  # type: ignore
+import hydra
+import torch
+from deepdiff import DeepDiff
+from omegaconf import DictConfig, OmegaConf
+from termcolor import colored
+from torch import nn
+from torch.optim.optimizer import Optimizer
+
+from lerobot.common.datasets.factory import make_dataset
+
+# TODO: Remove the import of maniskill
+from lerobot.common.datasets.lerobot_dataset import LeRobotDataset
+from lerobot.common.logger import Logger, log_output_dir
+from lerobot.common.policies.factory import make_policy
+from lerobot.common.policies.sac.modeling_sac import SACPolicy
+from lerobot.common.utils.utils import (
+    format_big_number,
+    get_global_random_state,
+    get_safe_torch_device,
+    init_hydra_config,
+    init_logging,
+    set_global_random_state,
+    set_global_seed,
+)
+from lerobot.scripts.server.buffer import (
+    ReplayBuffer,
+    concatenate_batch_transitions,
+    move_state_dict_to_device,
+    move_transition_to_device,
+)
+
+logging.basicConfig(level=logging.INFO)
+# Initialize these in the main process
+# transition_queue = Queue(maxsize=1_000_000)  # Set a maximum size
+# interaction_message_queue = Queue(maxsize=1_000_000)  # Set a maximum size
+policy_lock = Lock()
+replay_buffer_lock = Lock()
+offline_replay_buffer_lock = Lock()
+# logging_queue = Queue(maxsize=1_000_000)  # Set a maximum size
+
+def handle_resume_logic(cfg: DictConfig, out_dir: str) -> DictConfig:
+    if not cfg.resume:
+        if Logger.get_last_checkpoint_dir(out_dir).exists():
+            raise RuntimeError(
+                f"Output directory {Logger.get_last_checkpoint_dir(out_dir)} already exists. "
+                "Use `resume=true` to resume training."
+            )
+        return cfg
+
+    # if resume == True
+    checkpoint_dir = Logger.get_last_checkpoint_dir(out_dir)
+    if not checkpoint_dir.exists():
+        raise RuntimeError(f"No model checkpoint found in {checkpoint_dir} for resume=True")
+
+    checkpoint_cfg_path = str(Logger.get_last_pretrained_model_dir(out_dir) / "config.yaml")
+    logging.info(
+        colored(
+            "Resume=True detected, resuming previous run",
+            color="yellow",
+            attrs=["bold"],
+        )
+    )
+
+    checkpoint_cfg = init_hydra_config(checkpoint_cfg_path)
+    diff = DeepDiff(OmegaConf.to_container(checkpoint_cfg), OmegaConf.to_container(cfg))
+
+    if "values_changed" in diff and "root['resume']" in diff["values_changed"]:
+        del diff["values_changed"]["root['resume']"]
+
+    if len(diff) > 0:
+        logging.warning(
+            f"Differences between the checkpoint config and the provided config detected: \n{pformat(diff)}\n"
+            "Checkpoint configuration takes precedence."
+        )
+
+    checkpoint_cfg.resume = True
+    return checkpoint_cfg
+
+
+def load_training_state(
+    cfg: DictConfig,
+    logger: Logger,
+    optimizers: Optimizer | dict,
+):
+    if not cfg.resume:
+        return None, None
+
+    training_state = torch.load(logger.last_checkpoint_dir / logger.training_state_file_name)
+
+    if isinstance(training_state["optimizer"], dict):
+        assert set(training_state["optimizer"].keys()) == set(optimizers.keys())
+        for k, v in training_state["optimizer"].items():
+            optimizers[k].load_state_dict(v)
+    else:
+        optimizers.load_state_dict(training_state["optimizer"])
+
+    set_global_random_state({k: training_state[k] for k in get_global_random_state()})
+    return training_state["step"], training_state["interaction_step"]
+
+
+def log_training_info(cfg: DictConfig, out_dir: str, policy: nn.Module) -> None:
+    num_learnable_params = sum(p.numel() for p in policy.parameters() if p.requires_grad)
+    num_total_params = sum(p.numel() for p in policy.parameters())
+
+    log_output_dir(out_dir)
+    logging.info(f"{cfg.env.task=}")
+    logging.info(f"{cfg.training.online_steps=}")
+    logging.info(f"{num_learnable_params=} ({format_big_number(num_learnable_params)})")
+    logging.info(f"{num_total_params=} ({format_big_number(num_total_params)})")
+
+
+def initialize_replay_buffer(cfg: DictConfig, logger: Logger, device: str) -> ReplayBuffer:
+    if not cfg.resume:
+        return ReplayBuffer(
+            capacity=cfg.training.online_buffer_capacity,
+            device=device,
+            state_keys=cfg.policy.input_shapes.keys(),
+            storage_device=device,
+            use_shared_memory=True
+        )
+
+    dataset = LeRobotDataset(
+        repo_id=cfg.dataset_repo_id, local_files_only=True, root=logger.log_dir / "dataset"
+    )
+    return ReplayBuffer.from_lerobot_dataset(
+        lerobot_dataset=dataset,
+        capacity=cfg.training.online_buffer_capacity,
+        device=device,
+        state_keys=cfg.policy.input_shapes.keys(),
+        use_shared_memory=True
+    )
+
+
+def start_learner_threads(
+    cfg: DictConfig,
+    device: str,
+    replay_buffer: ReplayBuffer,
+    offline_replay_buffer: ReplayBuffer,
+    batch_size: int,
+    optimizers: dict,
+    policy: SACPolicy,
+    log_dir: Path,
+    transition_queue: Queue,
+    interaction_message_queue: Queue,
+    logging_queue: Queue,
+    resume_optimization_step: int | None = None,
+    resume_interaction_step: int | None = None,
+) -> None:
+    actor_ip = cfg.actor_learner_config.actor_ip
+    port = cfg.actor_learner_config.port
+
+    # Move policy to shared memory
+    policy.share_memory()
+
+    server_process = Process(
+        target=stream_transitions_from_actor,
+        args=(
+            transition_queue,
+            interaction_message_queue,
+            actor_ip,
+            port,
+        ),
+        daemon=True,
+    )
+
+    transition_process = Process(
+        target=train_offpolicy_rl,
+        daemon=True,
+        args=(
+            cfg,
+            replay_buffer,
+            offline_replay_buffer,
+            batch_size,
+            optimizers,
+            policy,
+            log_dir,
+            resume_optimization_step,
+        ),
+    )
+
+    param_push_process = Process(
+        target=learner_push_parameters,
+        args=(
+            policy,
+            actor_ip,
+            port,
+            15
+        ),
+        daemon=True,
+    )
+
+    fill_replay_buffers_process = Process(
+        target=fill_replay_buffers,
+        args=(
+            replay_buffer,
+            offline_replay_buffer,
+            transition_queue,
+            interaction_message_queue,
+            logging_queue,
+            resume_interaction_step,
+            device,
+        )
+    )
+
+    return server_process, transition_process, param_push_process, fill_replay_buffers_process
+
+
+
+def stream_transitions_from_actor(
+    transition_queue: Queue,
+    interaction_message_queue: Queue,
+    host: str,
+    port: int,
+):
+    """
+    Runs a gRPC client that listens for transition and interaction messages from an Actor service.
+
+    This function establishes a gRPC connection with the given `host` and `port`, then continuously
+    streams transition data from the `ActorServiceStub`. The received transition data is deserialized
+    and stored in a queue (`transition_queue`). Similarly, interaction messages are also deserialized
+    and stored in a separate queue (`interaction_message_queue`).
+
+    Args:
+        host (str, optional): The IP address or hostname of the gRPC server. Defaults to `"127.0.0.1"`.
+        port (int, optional): The port number on which the gRPC server is running. Defaults to `50051`.
+
+    """
+    # NOTE: This is waiting for the handshake to be done
+    # In the future we will do it in a canonical way with a proper handshake
+    time.sleep(10)
+    channel = grpc.insecure_channel(
+        f"{host}:{port}",
+        options=[("grpc.max_send_message_length", -1), ("grpc.max_receive_message_length", -1)],
+    )
+    stub = hilserl_pb2_grpc.ActorServiceStub(channel)
+    while True:
+        try:
+            for response in stub.StreamTransition(hilserl_pb2.Empty()):
+                if response.HasField("transition"):
+                    buffer = io.BytesIO(response.transition.transition_bytes)
+                    transition = torch.load(buffer)
+                    transition_queue.put(transition)
+                if response.HasField("interaction_message"):
+                    content = pickle.loads(response.interaction_message.interaction_message_bytes)
+                    interaction_message_queue.put(content)
+        except grpc.RpcError:
+            time.sleep(2)  # Retry connection
+            continue
+
+
+def learner_push_parameters(
+    policy: nn.Module,
+    actor_host="127.0.0.1",
+    actor_port=50052,
+    seconds_between_pushes=5
+):
+    """
+    As a client, connect to the Actor's gRPC server (ActorService)
+    and periodically push new parameters.
+    """
+    time.sleep(10)
+    channel = grpc.insecure_channel(
+        f"{actor_host}:{actor_port}",
+        options=[("grpc.max_send_message_length", -1), ("grpc.max_receive_message_length", -1)],
+    )
+    actor_stub = hilserl_pb2_grpc.ActorServiceStub(channel)
+
+    while True:
+        with policy_lock:
+            params_dict = policy.actor.state_dict()
+            # if policy.config.vision_encoder_name is not None:
+            #     if policy.config.freeze_vision_encoder:
+            #         params_dict: dict[str, torch.Tensor] = {
+            #             k: v for k, v in params_dict.items() if not k.startswith("encoder.")
+            #         }
+            #     else:
+            #         raise NotImplementedError(
+            #             "Vision encoder is not frozen, we need to send the full model over the network which requires chunking the model."
+            #         )
+
+        params_dict = move_state_dict_to_device(params_dict, device="cpu")
+        # Serialize
+        buf = io.BytesIO()
+        torch.save(params_dict, buf)
+        params_bytes = buf.getvalue()
+
+        # Push them to the Actor's "SendParameters" method
+        logging.info("[LEARNER] Publishing parameters to the Actor")
+        response = actor_stub.SendParameters(hilserl_pb2.Parameters(parameter_bytes=params_bytes))  # noqa: F841
+        time.sleep(seconds_between_pushes)
+
+
+
+def fill_replay_buffers(
+    replay_buffer: ReplayBuffer,
+    offline_replay_buffer: ReplayBuffer,
+    transition_queue: Queue,
+    interaction_message_queue: Queue,
+    logger_queue: Queue,
+    resume_interaction_step: int | None,
+    device: str,
+):
+    while True:
+        while not transition_queue.empty():
+            transition_list = transition_queue.get()  # Increase timeout
+            for transition in transition_list:
+                transition = move_transition_to_device(transition, device=device)
+                with replay_buffer_lock:
+                    replay_buffer.add(**transition)
+
+                if transition.get("complementary_info", {}).get("is_intervention"):
+                    with offline_replay_buffer_lock:
+                        offline_replay_buffer.add(**transition)
+            
+        while not interaction_message_queue.empty():
+            interaction_message = interaction_message_queue.get()
+            # If cfg.resume, shift the interaction step with the last checkpointed step in order to not break the logging
+            if resume_interaction_step is not None:
+                interaction_message["Interaction step"] += resume_interaction_step 
+            logger_queue.put({
+                'info': interaction_message,
+                'step_key': "Interaction step"
+            })
+
+
+def check_nan_in_transition(observations: torch.Tensor, actions: torch.Tensor, next_state: torch.Tensor):
+    for k in observations:
+        if torch.isnan(observations[k]).any():
+            logging.error(f"observations[{k}] contains NaN values")
+    for k in next_state:
+        if torch.isnan(next_state[k]).any():
+            logging.error(f"next_state[{k}] contains NaN values")
+    if torch.isnan(actions).any():
+        logging.error("actions contains NaN values")
+
+
+def train_offpolicy_rl(
+    cfg,
+    replay_buffer: ReplayBuffer,
+    offline_replay_buffer: ReplayBuffer,
+    batch_size: int,
+    optimizers: dict[str, torch.optim.Optimizer],
+    policy: nn.Module,
+    log_dir: Path,
+    logging_queue: Queue,
+    resume_optimization_step: int | None = None,
+):
+    """
+    Handles data transfer from the actor to the learner, manages training updates,
+    and logs training progress in an online reinforcement learning setup.
+
+    This function continuously:
+    - Transfers transitions from the actor to the replay buffer.
+    - Logs received interaction messages.
+    - Ensures training begins only when the replay buffer has a sufficient number of transitions.
+    - Samples batches from the replay buffer and performs multiple critic updates.
+    - Periodically updates the actor, critic, and temperature optimizers.
+    - Logs training statistics, including loss values and optimization frequency.
+
+    **NOTE:**
+    - This function performs multiple responsibilities (data transfer, training, and logging).
+      It should ideally be split into smaller functions in the future.
+    - Due to Python's **Global Interpreter Lock (GIL)**, running separate threads for different tasks
+      significantly reduces performance. Instead, this function executes all operations in a single thread.
+
+    Args:
+        cfg: Configuration object containing hyperparameters.
+        device (str): The computing device (`"cpu"` or `"cuda"`).
+        replay_buffer (ReplayBuffer): The primary replay buffer storing online transitions.
+        offline_replay_buffer (ReplayBuffer): An additional buffer for offline transitions.
+        batch_size (int): The number of transitions to sample per training step.
+        optimizers (Dict[str, torch.optim.Optimizer]): A dictionary of optimizers (`"actor"`, `"critic"`, `"temperature"`).
+        policy (nn.Module): The reinforcement learning policy with critic, actor, and temperature parameters.
+        log_dir (Path): The directory to save the log files.
+        resume_optimization_step (int | None): In the case of resume training, start from the last optimization step reached.
+        resume_interaction_step (int | None): In the case of resume training, shift the interaction step with the last saved step in order to not break logging.
+    """
+    # NOTE: This function doesn't have a single responsibility, it should be split into multiple functions
+    # in the future. The reason why we did that is the  GIL in Python. It's super slow the performance
+    # are divided by 200. So we need to have a single thread that does all the work.
+    time.time()
+    logging.info("Starting learner thread")
+    optimization_step = resume_optimization_step if resume_optimization_step is not None else 0
+
+    # Wait for stream process to be ready
+    while True:
+
+        with replay_buffer_lock:
+            logging.info(f"Size of replay buffer: {len(replay_buffer)}")
+            if len(replay_buffer) < cfg.training.online_step_before_learning:
+                time.sleep(1)
+                continue
+
+        # logging.info(f"Size of replay buffer: {len(replay_buffer)}")
+        # logging.info(f"Size of offline replay buffer: {len(offline_replay_buffer)}")
+
+        image_features, next_image_features = None, None
+        time_for_one_optimization_step = time.time()
+        for _ in range(cfg.policy.utd_ratio - 1):
+            with replay_buffer_lock:
+                batch = replay_buffer.sample(batch_size)
+
+            if cfg.dataset_repo_id is not None:
+                with offline_replay_buffer_lock:
+                    batch_offline = offline_replay_buffer.sample(batch_size)
+                batch = concatenate_batch_transitions(batch, batch_offline)
+
+            actions = batch["action"]
+            rewards = batch["reward"]
+            observations = batch["state"]
+            next_observations = batch["next_state"]
+            done = batch["done"]
+            check_nan_in_transition(observations=observations, actions=actions, next_state=next_observations)
+
+            # Precompute encoder features from the frozen vision encoder if enabled
+            if policy.config.vision_encoder_name is not None and policy.config.freeze_vision_encoder:
+                with torch.no_grad():
+                    image_features = (
+                        policy.actor.encoder(observations)
+                        if policy.actor.encoder is not None
+                        else None
+                    )
+                    next_image_features = (
+                        policy.actor.encoder(next_observations)
+                        if policy.actor.encoder is not None
+                        else None
+                    )
+
+            with policy_lock:
+                loss_critic = policy.compute_loss_critic(
+                    observations=observations,
+                    actions=actions,
+                    rewards=rewards,
+                    next_observations=next_observations,
+                    done=done,
+                    image_features=image_features,
+                    next_image_features=next_image_features,
+                )
+                optimizers["critic"].zero_grad()
+                loss_critic.backward()
+                optimizers["critic"].step()
+
+            with replay_buffer_lock:
+                batch = replay_buffer.sample(batch_size)
+
+            if cfg.dataset_repo_id is not None:
+                with offline_replay_buffer_lock:
+                    batch_offline = offline_replay_buffer.sample(batch_size)
+                batch = concatenate_batch_transitions(
+                    left_batch_transitions=batch, right_batch_transition=batch_offline
+                )
+
+        actions = batch["action"]
+        rewards = batch["reward"]
+        observations = batch["state"]
+        next_observations = batch["next_state"]
+        done = batch["done"]
+
+        check_nan_in_transition(observations=observations, actions=actions, next_state=next_observations)
+
+        # Precompute encoder features from the frozen vision encoder if enabled
+        if policy.config.vision_encoder_name is not None and policy.config.freeze_vision_encoder:
+            with torch.no_grad():
+                image_features = (
+                    policy.actor.encoder(observations)
+                    if policy.actor.encoder is not None
+                    else None
+                )
+                next_image_features = (
+                    policy.actor.encoder(next_observations)
+                    if policy.actor.encoder is not None
+                    else None
+                )
+        with policy_lock:
+            loss_critic = policy.compute_loss_critic(
+                observations=observations,
+                actions=actions,
+                rewards=rewards,
+                next_observations=next_observations,
+                done=done,
+                image_features=image_features,
+                next_image_features=next_image_features,
+            )
+            optimizers["critic"].zero_grad()
+            loss_critic.backward()
+            optimizers["critic"].step()
+
+        training_infos = {}
+        training_infos["loss_critic"] = loss_critic.item()
+
+        if optimization_step % cfg.training.policy_update_freq == 0:
+            for _ in range(cfg.training.policy_update_freq):
+                with policy_lock:
+                    loss_actor = policy.compute_loss_actor(observations=observations, image_features=image_features)
+
+                    optimizers["actor"].zero_grad()
+                    loss_actor.backward()
+                    optimizers["actor"].step()
+
+                    training_infos["loss_actor"] = loss_actor.item()
+
+                loss_temperature = policy.compute_loss_temperature(observations=observations, image_features=image_features)
+                optimizers["temperature"].zero_grad()
+                loss_temperature.backward()
+                optimizers["temperature"].step()
+
+                training_infos["loss_temperature"] = loss_temperature.item()
+
+        policy.update_target_networks()
+        if optimization_step % cfg.training.log_freq == 0:
+            training_infos["Optimization step"] = optimization_step
+            logging_queue.put({
+                'info': training_infos,
+                'step_key': "Optimization step"
+            })
+
+        time_for_one_optimization_step = time.time() - time_for_one_optimization_step
+        frequency_for_one_optimization_step = 1 / (time_for_one_optimization_step + 1e-9)
+
+        logging.info(f"[LEARNER] Optimization frequency loop [Hz]: {frequency_for_one_optimization_step}")
+
+        optimization_step += 1
+        if optimization_step % cfg.training.log_freq == 0:
+            logging.info(f"[LEARNER] Number of optimization step: {optimization_step}")
+
+        if cfg.training.save_checkpoint and (
+            optimization_step % cfg.training.save_freq == 0 or optimization_step == cfg.training.online_steps
+        ):
+            logging.info(f"Checkpoint policy after step {optimization_step}")
+            # Note: Save with step as the identifier, and format it to have at least 6 digits but more if
+            # needed (choose 6 as a minimum for consistency without being overkill).
+            _num_digits = max(6, len(str(cfg.training.online_steps)))
+            step_identifier = f"{optimization_step:0{_num_digits}d}"
+            logging_queue.put({
+                'checkpoint': {
+                    'step': optimization_step,
+                    'identifier': step_identifier,
+                }
+            })
+
+            # TODO : temporarly save replay buffer here, remove later when on the robot
+            # We want to control this with the keyboard inputs
+            dataset_dir = log_dir / "dataset"
+            if dataset_dir.exists() and dataset_dir.is_dir():
+                shutil.rmtree(
+                    dataset_dir,
+                )
+            with replay_buffer_lock:
+                replay_buffer.to_lerobot_dataset(
+                    cfg.dataset_repo_id, fps=cfg.fps, root=dataset_dir
+                )
+
+            logging.info("Resume training")
+
+
+def make_optimizers_and_scheduler(cfg, policy: nn.Module):
+    """
+    Creates and returns optimizers for the actor, critic, and temperature components of a reinforcement learning policy.
+
+    This function sets up Adam optimizers for:
+    - The **actor network**, ensuring that only relevant parameters are optimized.
+    - The **critic ensemble**, which evaluates the value function.
+    - The **temperature parameter**, which controls the entropy in soft actor-critic (SAC)-like methods.
+
+    It also initializes a learning rate scheduler, though currently, it is set to `None`.
+
+    **NOTE:**
+    - If the encoder is shared, its parameters are excluded from the actor's optimization process.
+    - The policy's log temperature (`log_alpha`) is wrapped in a list to ensure proper optimization as a standalone tensor.
+
+    Args:
+        cfg: Configuration object containing hyperparameters.
+        policy (nn.Module): The policy model containing the actor, critic, and temperature components.
+
+    Returns:
+        Tuple[Dict[str, torch.optim.Optimizer], Optional[torch.optim.lr_scheduler._LRScheduler]]:
+        A tuple containing:
+        - `optimizers`: A dictionary mapping component names ("actor", "critic", "temperature") to their respective Adam optimizers.
+        - `lr_scheduler`: Currently set to `None` but can be extended to support learning rate scheduling.
+
+    """
+    optimizer_actor = torch.optim.Adam(
+        # NOTE: Handle the case of shared encoder where the encoder weights are not optimized with the gradient of the actor
+        params=policy.actor.parameters_to_optimize,
+        lr=policy.config.actor_lr,
+    )
+    optimizer_critic = torch.optim.Adam(
+        params=policy.critic_ensemble.parameters(), lr=policy.config.critic_lr
+    )
+    optimizer_temperature = torch.optim.Adam(params=[policy.log_alpha], lr=policy.config.critic_lr)
+    lr_scheduler = None
+    optimizers = {
+        "actor": optimizer_actor,
+        "critic": optimizer_critic,
+        "temperature": optimizer_temperature,
+    }
+    return optimizers, lr_scheduler
+
+
+def train(cfg: DictConfig, out_dir: str | None = None, job_name: str | None = None):
+
+    # Initialize multiprocessing with spawn method for better compatibility
+    set_start_method('spawn', force=True)
+
+    if out_dir is None:
+        raise NotImplementedError()
+    if job_name is None:
+        raise NotImplementedError()
+
+    init_logging()
+    logging.info(pformat(OmegaConf.to_container(cfg)))
+
+    # Create our logger instance in the main process
+    logger = Logger(cfg, out_dir, wandb_job_name=job_name)
+    cfg = handle_resume_logic(cfg, out_dir)
+
+    set_global_seed(cfg.seed)
+
+    device = get_safe_torch_device(cfg.device, log=True)
+
+    torch.backends.cudnn.benchmark = True
+    torch.backends.cuda.matmul.allow_tf32 = True
+
+    logging.info("make_policy")
+
+    ### Instantiate the policy in both the actor and learner processes
+    ### To avoid sending a SACPolicy object through the port, we create a policy intance
+    ### on both sides, the learner sends the updated parameters every n steps to update the actor's parameters
+    # TODO: At some point we should just need make sac policy
+
+    policy: SACPolicy = make_policy(
+        hydra_cfg=cfg,
+        # dataset_stats=offline_dataset.meta.stats if not cfg.resume else None,
+        # Hack: But if we do online traning, we do not need dataset_stats
+        dataset_stats=None,
+        pretrained_policy_name_or_path=str(logger.last_pretrained_model_dir) if cfg.resume else None,
+    )
+    # compile policy
+    # policy = torch.compile(policy)
+    assert isinstance(policy, nn.Module)
+
+    optimizers, lr_scheduler = make_optimizers_and_scheduler(cfg, policy)
+    resume_optimization_step, resume_interaction_step = load_training_state(cfg, logger, optimizers)
+
+    log_training_info(cfg, out_dir, policy)
+
+    replay_buffer = initialize_replay_buffer(cfg, logger, device)
+    batch_size = cfg.training.batch_size
+    offline_replay_buffer = None
+
+    if cfg.dataset_repo_id is not None:
+        logging.info("make_dataset offline buffer")
+        offline_dataset = make_dataset(cfg)
+        logging.info("Convertion to a offline replay buffer")
+        active_action_dims = [i for i, mask in enumerate(cfg.env.wrapper.joint_masking_action_space) if mask]
+        offline_replay_buffer = ReplayBuffer.from_lerobot_dataset(
+            offline_dataset,
+            device=device,
+            state_keys=cfg.policy.input_shapes.keys(),
+            action_mask=active_action_dims,
+            action_delta=cfg.env.wrapper.delta_action,
+            use_shared_memory=True
+        )
+        batch_size = batch_size // 2
+
+    transition_queue = Queue(maxsize=1_000_000)  # Set a maximum size
+    interaction_message_queue = Queue(maxsize=1_000_000)  # Set a maximum size
+    logging_queue = Queue(maxsize=1_000_000)  # Set a maximum size
+
+    processes = start_learner_threads(
+        cfg,
+        device,
+        replay_buffer,
+        offline_replay_buffer,
+        batch_size,
+        optimizers,
+        policy,
+        logger.log_dir,
+        transition_queue,
+        interaction_message_queue,
+        logging_queue,
+        resume_optimization_step,
+        resume_interaction_step,
+    )
+
+
+    # Consume log messages from the logging_queue in the main process
+    for p in processes:
+        p.start()
+
+    latest_interaction_step = resume_interaction_step if resume_interaction_step is not None else 0
+    while True:
+        try:
+            message = logging_queue.get(timeout=1)
+            if 'checkpoint' in message:
+                ckpt = message['checkpoint']
+                logger.save_checkpoint(
+                    ckpt['step'],
+                    policy,
+                    optimizers,
+                    scheduler=None,
+                    identifier=ckpt['identifier'],
+                    interaction_step=latest_interaction_step,
+                )
+            else:
+                if 'Interaction step' in message['info']:
+                    latest_interaction_step = message['info']['Interaction step']
+                logger.log_dict(
+                    message['info'],
+                    mode="train",
+                    custom_step_key=message['step_key']
+                )
+        except queue.Empty:
+            continue
+        except KeyboardInterrupt:
+            # Cleanup any remaining processes (if you want to terminate them here)
+            for p in processes:
+                if p.is_alive():
+                    p.terminate()
+                    p.join()
+            break
+
+
+@hydra.main(version_base="1.2", config_name="default", config_path="../../configs")
+def train_cli(cfg: dict):
+    train(
+        cfg,
+        out_dir=hydra.core.hydra_config.HydraConfig.get().run.dir,
+        job_name=hydra.core.hydra_config.HydraConfig.get().job.name,
+    )
+
+
+if __name__ == "__main__":
+    train_cli()