diff --git a/qadence/extensions.py~ b/qadence/extensions.py~
deleted file mode 100644
index 4acb2a690..000000000
--- a/qadence/extensions.py~
+++ /dev/null
@@ -1,84 +0,0 @@
-from __future__ import annotations
-
-import importlib
-from typing import TypeVar
-
-from qadence.backend import Backend
-from qadence.blocks import (
-    AbstractBlock,
-)
-from qadence.types import BackendName, DiffMode
-
-TAbstractBlock = TypeVar("TAbstractBlock", bound=AbstractBlock)
-
-
-def _get_available_backends() -> dict:
-    res = {}
-    for backend in BackendName.list():
-        module_path = f"backends.{backend}.backend"
-        try:
-            module = importlib.import_module(module_path)
-            BackendCls = getattr(module, "Backend")
-            res[backend] = BackendCls
-        except (ImportError, ModuleNotFoundError):
-            pass
-
-    return res
-
-
-def _supported_gates(name: BackendName | str) -> list[TAbstractBlock]:
-    from qadence import operations
-
-    name = str(BackendName(name).name.lower())
-
-    try:
-        module = importlib.import_module(f"backends.{name}")
-    except KeyError:
-        pass
-    _supported_gates = getattr(module, "supported_gates", None)
-    assert (
-        _supported_gates is not None
-    ), f"{name} backend should define a 'supported_gates' variable"
-    return [getattr(operations, gate) for gate in _supported_gates]
-
-
-def _get_gpsr_fns() -> dict:
-    # avoid circular import
-    from qadence.backends.gpsr import general_psr
-
-    return {DiffMode.GPSR: general_psr}
-
-
-def _set_backend_config(backend: Backend, diff_mode: DiffMode) -> None:
-    """_summary_
-
-    Args:
-        backend (Backend): _description_
-        diff_mode (DiffMode): _description_
-    """
-
-    # When using PSR with any backend or the backends Pulser or Braket,
-    #  we have to use gate-level parameters
-    if backend.name != [BackendName.PULSER, BackendName.BRAKET]:
-        backend.config._use_gate_params = (
-            diff_mode == DiffMode.GPSR
-        )  # or diff_mode == DiffMode.AGPSR
-
-    # BRAKET and PULSER only supports GPSR
-    if backend.name in [BackendName.BRAKET, BackendName.PULSER]:
-        backend.config._use_gate_params = True
-
-
-# if proprietary qadence_plus is available import the
-# right function since more backends are supported
-try:
-    module = importlib.import_module("qadence_plus._backend_utils")
-    get_available_backends = getattr(module, "get_available_backends")
-    supported_gates = getattr(module, "supported_gates")
-    get_gpsr_fns = getattr(module, "get_gpsr_fns")
-    set_backend_config = getattr(module, "set_backend_config")
-except ModuleNotFoundError:
-    get_available_backends = _get_available_backends
-    supported_gates = _supported_gates
-    get_gpsr_fns = _get_gpsr_fns
-    set_backend_config = _set_backend_config