diff --git a/n3fit/src/n3fit/backends/keras_backend/MetaModel.py b/n3fit/src/n3fit/backends/keras_backend/MetaModel.py
index afcc4b6dad..ddd010b89a 100644
--- a/n3fit/src/n3fit/backends/keras_backend/MetaModel.py
+++ b/n3fit/src/n3fit/backends/keras_backend/MetaModel.py
@@ -9,6 +9,7 @@
 import re
 
 from keras import Variable
+from keras import backend as K
 from keras import ops as Kops
 from keras import optimizers as Kopt
 from keras.models import Model
@@ -16,11 +17,6 @@
 
 import n3fit.backends.keras_backend.operations as op
 
-# Starting with TF 2.16, a memory leak in TF https://github.com/tensorflow/tensorflow/issues/64170
-# makes jit compilation unusable in GPU.
-# Before TF 2.16 it was set to `False` by default. From 2.16 onwards, it is set to `True`
-JIT_COMPILE = False
-
 # Define in this dictionary new optimizers as well as the arguments they accept
 # (with default values if needed be)
 optimizers = {
@@ -296,13 +292,16 @@ def compile(
 
         # If given target output is None, target_output is unnecesary, save just a zero per output
         if target_output is None:
-            self.target_tensors = [op.numpy_to_tensor(np.zeros((1, 1))) for i in self.output_shape]
+            self.target_tensors = [op.numpy_to_tensor(np.zeros((1, 1))) for _ in self.output_shape]
         else:
             if not isinstance(target_output, list):
                 target_output = [target_output]
             self.target_tensors = target_output
 
-        super().compile(optimizer=opt, loss=loss, jit_compile=JIT_COMPILE)
+        # For debug purposes it may be interesting to set in the compile call
+        # jit_compile = False
+        # run_eager = True
+        super().compile(optimizer=opt, loss=loss)
 
     def set_masks_to(self, names, val=0.0):
         """Set all mask value to the selected value
diff --git a/n3fit/src/n3fit/backends/keras_backend/internal_state.py b/n3fit/src/n3fit/backends/keras_backend/internal_state.py
index 4235a73473..23d9ed3819 100644
--- a/n3fit/src/n3fit/backends/keras_backend/internal_state.py
+++ b/n3fit/src/n3fit/backends/keras_backend/internal_state.py
@@ -21,7 +21,7 @@
 log = logging.getLogger(__name__)
 
 # Prepare Keras-backend dependent functions
-if K.backend() == "torch":
+if K.backend() in ("torch", "jax"):
 
     def set_eager(flag=True):
         """Pytorch is eager by default"""
diff --git a/n3fit/src/n3fit/backends/keras_backend/operations.py b/n3fit/src/n3fit/backends/keras_backend/operations.py
index ae65e1f1de..3f5f9c5736 100644
--- a/n3fit/src/n3fit/backends/keras_backend/operations.py
+++ b/n3fit/src/n3fit/backends/keras_backend/operations.py
@@ -23,8 +23,6 @@
     equally operations are automatically converted to layers when used as such.
 """
 
-from typing import Optional
-
 from keras import backend as K
 from keras import ops as Kops
 from keras.layers import ELU, Input
@@ -37,9 +35,12 @@
 
 # Backend dependent functions and operations
 if K.backend() == "torch":
-    tensor_to_numpy_or_python = lambda x: x.detach().numpy()
+    tensor_to_numpy_or_python = lambda x: x.detach().cpu().numpy()
+    decorator_compiler = lambda f: f
+elif K.backend() == "jax":
+    tensor_to_numpy_or_python = lambda x: np.array(x.block_until_ready())
     decorator_compiler = lambda f: f
-else:
+elif K.backend() == "tensorflow":
     tensor_to_numpy_or_python = lambda x: x.numpy()
     lambda ret: {k: i.numpy() for k, i in ret.items()}
     import tensorflow as tf
diff --git a/n3fit/src/n3fit/layers/observable.py b/n3fit/src/n3fit/layers/observable.py
index 29c5754ecc..14a7c8cd15 100644
--- a/n3fit/src/n3fit/layers/observable.py
+++ b/n3fit/src/n3fit/layers/observable.py
@@ -225,7 +225,7 @@ def compute_float_mask(bool_mask):
     """
     # Create a tensor with the shape (**bool_mask.shape, num_active_flavours)
     masked_to_full = []
-    for idx in np.argwhere(np.array(bool_mask)):
+    for idx in np.argwhere(op.tensor_to_numpy_or_python(bool_mask)):
         temp_matrix = np.zeros(bool_mask.shape)
         temp_matrix[tuple(idx)] = 1
         masked_to_full.append(temp_matrix)